Wall Framing, The First Hint of a House

Exterior Shell, The Walls

We have been long awaiting the day when we would raise our first wall of the tiny house, and it finally arrived! Right after we finished the subfloor we though we were ready to go, but quickly realized that we needed to do a bit more planning. As I’ve mentioned, we bought the plans to hOMe, built and designed by the Morrisons; however, with the drastic changes we made to the interior floor plan came a few small tweaks to the framing in terms of window positioning and the exact location of the front door. The little tweaks were enough to prevent us from completely following hOMe’s framing plans though, and we had to go back to the drawing board. As a fun little add on before heading back to the house to crack open Google Sketch-up, we decided to lay out our floor plan on our completed subfloor using painter’s tape. Here is the very first tour of our tiny house, on YouTube!

So, we went back to the drawing board and confirmed the position of each and every stud, and the exact position of each window and door. Tim is the SketchUp guy, so he worked on this, and it was very time consuming. I would highly recommend this software program though, it has been instrumental in our planning. Tim will write a post about his experience with it soon. We made an estimate for how many 2″ x 4″s we IMG_9489would need, and the number of those that would be 8′, 10′, 12′, 14′ and 16′ long.
The next day, we purchased the 2″ x 4″s, and organized them into stacks according to length, under our trailer – a great way to keep them out of the way and accessible at the same time. At that point, there really wasn’t anything standing between us and our first wall anymore. I don’t know why this was so intimidating… I feel like everything up to this point was just manual labour, that really anyone could do if they have time and willingness. There was something about the framing though that make me feel like we should have someone else there to at least supervise. As it turns out, of course, my worry was all for naught. Framing is SUPER fun, and very straight forward once you just dive into it. It’s sort of comparable to a puzzle of sorts, figuring out where everything goes and each piece fitting perfectly with its neighbours.

Labelled photo of framing for one of our windows. The bottom plate is down below the field of view. I love Microsoft Paint :)

Labelled photo of framing for one of our windows. The bottom plate is down below the field of view. I love Microsoft Paint 🙂

I’m no carpenter, but all you really need to know is that there are four types of studs: a regular stud, a king stud, a trimmer stud, and a cripple stud. Regular studs run through the entire wall space from the bottom plate to the top plate, and provide the structural skeleton of your wall. Often, they’re positioned on 16″ centres, but in our build we are using 24″ inch centres. The remaining three types are used to handle windows and doors. Since windows and doors are not meant to be structural, load bearing surfaces, they need help from the framing. The window header acts like a bridge that runs over the top of the window, transferring the above load to two trimmer studs at either end of the window. Trimmer studs run from top plate to bottom plate but they pinch a header, and in the case of a window, they also pinch a sill. This breaks the trimmer into three pieces. Trimmer studs are also called jack studs by some people, and they are always buddied up with king studs. King studs, one on each side of the window (outside the trimmers, header and sill) tie together the entire window framing assembly to keep it all nice and straight, and add additional rigidity.

Cripple studs are just like regular studs, except they run from the bottom plate up to a window sill, OR from the top plate down to a header. They are positioned on the ever important 24″ centre lines, and would normally run all the way through the wall space, but windows and doors get in the way sometimes!

Google Sketch-Up framing model open on the laptop, and laying out our studs according to the plan.

Google Sketch-Up framing model open on the laptop, and laying out our studs according to the plan.

It is possible for a window and a door (or two windows!) to share king studs, which we did on both sides of our front door. If one of your window/door assembly studs lands close to a 24″ centre, it may be tempting to forgo putting in a cripple or another regular stud, but it is really important to do it anyway. When it comes time to put the exterior (and interior for that matter) sheathing up, you need to have studs right on those intervals as a nailing surface. If you don’t, you’ll have floating edges of plywood, and that will create major weaknesses in your wall with respect to moisture, and structural integrity. WITH that said though, it is possible for a king or trimmer stud to land on a 24″ centre, and act as a nailing surface for the sheathing. We also had this situation many times in our design, which is great, because studs that run double duty let us use less wood, and the wall is that much lighter.

18" (height) x 60" (width) window header dimensions.

18″ (height) x 60″ (width) window header dimensions.

 

 

A note on headers: the size of a header is proportional to the width of the opening it is bridging. The instructions in our plans communicated that a 4′ wide opening would need a 4″ x 4″ header, a 6′ wide opening would need a 4″ x 6″ header, an 8′ wide opening would need a 4″ x 8″ header, and so on. Of course, like regular ol’ 2″ x 4″s, all these call outs in reality are 1/2″ smaller in both directions. It seems though that you can’t always buy wood of these dimensions, so you have to get creative. The three windows that go along the top of our front wall are all 5′ wide, so we constructed 4″ x 6″ headers using two 2″ x 6″s, with a strip of 1/2″ plywood sandwiched in between. The three pieces were nailed together liberally.

First piece of the front wall, ready to raise.

First piece of the front wall, ready to raise.

So, with that information, we went about building the first piece of our wall, flat on the deck of the trailer. Once it was built, we then lifted it up and stood it in place where it needed to go. From start to finish, this first 16′ long piece took us two days to complete. The second piece, which was just over 12′ took us only 7 hours to build and raise. Thank you, learning curve 🙂 It’s important to have a brace ready to go once you get your wall raised, so it can stay in place without needing someone to hold it. It’s also equally important to nail on some blocks to the edge of the subfloor, to prevent the wall from sliding off the edge of the trailer when raising it.

Wall #1!

Wall #1!

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Tim, securing one piece of a wall to another. Using a ratchet strap around two studs of the adjoining pieces allows you get everything nice a snug before driving nails.

Tim, securing one piece of a wall to another. Using a ratchet strap around two studs of the adjoining pieces allows you get everything nice and snug before driving nails.

 

Tying the two pieces of wall together to form one cohesive unit wasn’t too hard. We are using what’s called a double top plate, which means that for each piece of adjoining wall, there’s an extra 2″x4″ stacked on top that is either longer or shorter than the regular top plate. Our first piece of wall was 16′ long, with a 12’3″ double top plate stacked on top. Our second piece of wall was 12’3″ with a 16′ double top plate stacked on top. When the two pieces come together, we can nail the double top plates together from above, and the seam between the two lies staggered and away from the seam of the two pieces of wall.

View from the tongue end of the trailer, front wall is on the right and back wall is on the left.

View from the tongue end of the trailer, front wall is on the right and back wall is on the left.

As you can see in the picture, the front wall is higher than the back wall – a difference of about 1’3″. This difference allows the roof to be sloped towards the back of the house, which is essential to prevent rain or snow from pooling on the roof. It makes sense for the slope to angle away from the front door too, so you don’t get soaked trying to get in on rainy days. The angle of the slope is what’s called a 2 and 12 (for every 12″ run/horizontal, there is a rise/vertical change of 2″) which converts to about 10°. A lot of people building tiny houses, and any house for that matter, use a gable style roof (peak in the centre, sloping down to either side). We think it makes more sense to go with the style in our plan, also known as a shed roof, because it allows the maximum amount of head room in the loft to be concentrated at one end. If you’re sitting in bed, chances are you’re going to be leaning against the headboard / wall, and your feet will be at the opposite end, so this configuration for head room is the best. Having the maximum head space in the centre would work if you like sitting in the centre of your bed, but really, when do you ever do that?

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Subfloor finitum.

Exterior Shell, Sub-floor

After much ado, the subfloor and its many components are finally done. It’s one of those things where a lot of hours go in, with not a whole lot to show for it. The last step after insulating all the spaces between the steel joists of the trailer was to lay down 3/4 inch tongue and groove plywood to cover the entire surface.

The first sheet of plywood!

The first sheet of plywood!

We started on September 10th (Day 16 of the build since bringing the trailer out to our site) and finished on Saturday, September 12th. It was the icing on the cake so to say, but even with the reward of having that clean slate to start raising walls on, my energy was waning during this part.

It is very gratifying to complete each step, but it is a challenge constantly having to check your expectations at the door in terms of how long things take and how tricky they will be. Little failures or overlooked details are constantly acquainting you with the many shades of humility.

OOPS! Nothing a little PL Premium won't fix.

OOPS! Nothing a little PL Premium won’t fix.

Mental fatigue is definitely a bigger challenge than physical fatigue with all of this, which is something I never would have guessed. A steady effort of holding objects in your mind in 3D and moving them around in different positions to be correctly placed is exhausting!

First thing first, we laid down more sill gasket on all the steel that would be in contact with the subfloor plywood. This is to prevent thermal bridging – a fancy term describing how a more conductive material (steel) creates a pathway for heat to be quickly transferred through a thermal barrier (the insulated subfloor). It makes sense… the steel joists are going to get cold, and they IMG_20150910_155249run up through the insulation to touch our floor. A heat thief if I ever saw one. So the sill gasket provides an insulating break between the steel and our floor. It should help a good bit. We tried using PL premium as an adhesive to stick the strips of sill gasket down, but it didn’t work very well. A few pieces of tuck tape were much more effective.

The 3/4″ tongue and groove (T&G) plywood came in 4′ x 8′ sheets. Each sheet has tongue along one of the 8′ sides, and groove along the other IMG_94388′ side. The top and bottom (the 4′ sides) are square. Each sheet is also
stamped with a “This Side Down” marker, which results in each sheet lying concave up. In the instructional video that came with our plans, it
was explained that the sheets of plywood must run their length perpendicular to the underlying strength axes (which in this case are the steel joists of the trailer).  It is also very important to stagger the sheets so that the seams don’t line up with one another, creating sustained linear weaknesses along which the structure can bend. Alternating our seams at 4′ intervals gave us the maximum strength and unity our subfloor was capable of having.

So to be clear, it wasn’t just me who was tired, Tim was pretty tapped out as well. He was in go-mode though to just power through, and didn’t even stop to take many pictures. I tried to snap a few here and there to make sure the process wasn’t completely lost in time. The fact that each sheet had to be oriented specifically to face down the right way, and to have the tongue of one sheet tying into the groove of the next meant that we had to be really careful about each individual cut we made with the circular saw. Once that cut was made there was no going back, and, like the rigid board insulation, each sheet of plywood is worth a pretty penny!

We used 1.5″ screws to tie down the sheets of plywood. Every six inches along the perimeter (into the wooden side rails) and every twelve inches in the field of each sheet was our pattern. For the screws in the field, we were back to those #$^*)(@$% self-tapping screws again, since we were attaching to the top sides of the steel joists.

Fifth times a charm?

Fifth time’s a charm?

I really SERIOUSLY can’t stress this enough: invest in your fasteners. It sucks to pay a premium on the small stuff, but it will be so, SO worth it. The same goes for drill bits. If you buy (unknowingly or not) poor quality screws and/or drill bits, they will snap. Repeatedly. We used over 200 self-tapping metal screws and maybe 150 wood screws in total, and I didn’t count how many of those were duds. After this though we’ll be done with metal, and be able to work exclusively with wood (at least until the metal roof goes on, but that won’t be nearly as thick as the 1/4″ steel in the trailer joists).

Mind the gap! Lolz

Mind the gap! Lolz

As was the frustration with the 2′ x 4′ side rails, the plywood was pretty bowed, which made it difficult to fit the tongue and groove together completely, and to keep all four corners square. An important thing to remember with this is that wood swells, so you can’t abut adjacent pieces tight to one another – leaving about 1/8″ gap all the way around each sheet allows the plywood room to swell and shrink with varying moisture levels. Not doing this can result in your floor buckling under your feet, which is obviously undesirable. Our carpenter’s square is 1/8″ thick, so that made it quick to check our placement. The thing to keep in mind with these gaps is that they are constantly adding on to your total length, with each piece that is laid. This slipped our minds at first, and actually caused us a bit of hassle.

This sheet didn't line up properly. We had to take the screws out and skim a strip off the end of the sheet in order to make room for the next piece.

This sheet didn’t line up properly. We had to take the screws out and skim a strip off the end of the sheet with the skill saw in order to make room for the next piece.

The steel joists are on 2′ centres, so, the ends of two neighbouring pieces of plywood must meet each other equally at the centre of each joist in order to have enough room for the screws to bite into the metal on each side. These joists are the only surfaces on which the pieces of plywood could be attached in the field, so each one needed to be shared 50/50. Successive 1/8″ gaps add up fast, and without taking them into account, you can end up with one piece of plywood hogging a steel joist, with no room for the next sheet to tie in!

Other mentionable quirks include routing holes to accommodate the pieces of threaded rod, and cutting out pieces to IMG_20150910_221159allow for our wheel wells. It seems that with rough carpentry, it doesn’t matter how precise you try to be, it’s impossible to have everything just so. What a positively fantastic exercise for the nit picky hair-splitter in me!

As you can see in the header photograph for this post, on the right hand side of the trailer we ended up having to cut narrow strips to finish off the entire surface – much like with the aluminum flashing on the underside of the trailer. It would have been so much nicer to have the trailer a perfect 8′ wide by 24′ long, side rails included; then we could lay full sheets with no modifications required. But I digress… Again, since the tongue is only on one side of each sheet, we were left with a lot of wood that didn’t have a tongue for us to work with. Tim being Tim (economical and creative) decided to fashion a tongue himself on the long 10″ wide strips we had cut to fill out that right hand side. All it took was a table saw, a bit of cleverness and elbow grease.

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A really great tip: take a speed square and pencil, and trace the edges of the steel joists onto the side rails prior to laying your plywood.IMG_20150910_174006 These lines can then be extended along the tops of your plywood so you can know exactly where the steel joists lie, and hence, where to sink your screws. It was a big help for us! We finished up the last few pieces and finally swept off our floor for the very first time. There were a few housekeeping tasks to clue up then, like trimming some of the perimeter overhanging edges of plywood, and using the grinder to cut off any of the snapped screw shanks left sticking up out of the floor. We also caulked around the threaded rod for good measure. All the cursing and frustration has been worth it, and we can now put in our order for 2′ x 4’s for our walls. Before you know it we’ll be raising the roof!

 

 

Tim taking it easy after a hard day's work.

Tim taking it easy after a hard day’s work.

Me, feeling proud :P

Me, feeling proud 😛

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An Insulation Sandwich to Stand On.

Exterior Shell, Sub-floor

After we finished installing the flashing, we had to close up the seams between all the lengthwise sheets, as well as gaps around hangers and the tongue. To do this, we used a special kind of duct tape IMG_9245made by IPG that is typically used in duct work or on chimneys. It’s heat resistant, which I thought was an added bonus, and it came in a roll of about 45 m (omg, finally something in metric). It also came with a hefty price tag though- $15 per roll, so we bought just one to see how it went. Turned it to be perfect for our needs, and we were able to do the entire trailer with just the one roll! The ‘aggressive adhesive’ lived up to its hype and I feel very confident that we’ve been meticulous enough about moisture and tiny intruder prevention. As a side note, it’s miraculous how well the volume of our purchases have been working out. Little waste makes us happy campers.

There was something very oddly pleasing and enjoyable about peeling the backing off of each strip of this stuff and sticking it to our flashing. Smooth lines, and no more IMG_9266gaps! Simple joys 😀 There was a scattered spot (in the area where we first began our flashing, when we still sucked at it) where the flashing was bowed a bit extra – in those places we beefed up the closure using caulking; PL Premium, to be exact. This stuff worked really well, I’d recommend it. IMG_20150903_154529We also used this stuff all around the perimeter of the axle section, and the hangers belonging to the leaf springs and equalizers. If there’s anywhere on the trailer with a higher risk of water infiltration, we figure it will be around the wheels, so that’s why we did that.

Ready for insulation!

Ready for insulation!

Since the caulking takes a little time to dry, we had to space this out a bit, and did it over two days: September 3rd and 4th. We were going to head straight home for the weekend then to recharge our batteries, but we decided to spend the afternoon on Friday the 4th getting the subfloor insulation started. Now, since I did the post on insulation in the research phase, I’ve learned a good bit more about it all. You might recall that we had said we were planning on rigid board (also known as code board) throughout, but at that time I had no idea how expensive the stuff was. Turns out, a 2″ thick 4′ x 8′ sheet is around $50 a pop. So to cut down costs, we tried to come up with a compromise for our subfloor, since it is probably the lowest risk area for heat loss. A lot more research ensued, and to be honest, I wasn’t really able to get a straight answer on anything.

In the plans we bought, the instructions did not include the seam taping that we did on our flashing. They said to use one layer of 2″ thick rigid board, and another layer on top of the first, of 1.5″ thick rigid board with a radiant barrier (shiny silver backing) on the side facing upward. This would allow for the required air space between the radiant barrier and the plywood subfloor in order to properly reflect radiant heat back into the house. No vapour barrier was used in their method on either side. My issue with all of this was that not taping the seams left the underside of the trailer too vulnerable. Also, using a radiant barrier in the floor didn’t make a whole lot of sense since the majority of heat loss would be happening through the roof – I would consider it up there but not in the floor. And lastly of course, the cost of all the rigid was daunting. So we bought some Roxul mineral wool batts – really cool stuff! IMG_20150827_162456IMG_20150904_140455It’s made from volcanic rock (basalt) and steel slag, spun into a fibrous mass which is basically fireproof, highly moisture resistant, and much healthier and practical than fibreglass. It is recommended to install a vapour barrier with it though.

With all of this insulation research, my biggest concern was vapour barriers and if / when to use them. Theoretically, in a predominantly cold climate, you want to place a single vapour barrier on the warm side of your insulation (towards the inside) in order to block moist air moving from inside the house, into the wall / floor space and condensing on the insulation or exterior sheathing once it meets the cooler temperature towards the exterior. Since we had sealed the bottom, moisture and water vapour were effectively blocked from that side, so if any moisture got in, it would be kinda stuck with a vapour barrier on top as well. I was worried that putting that vapour barrier / retardant on the top would run the risk of turning our subfloor into a big ziplock bag of mould, if any vapour was able to sneak inside somehow. Oh the stresses… we decided against it in the end and went back to plan A to fill the entire trailer with rigid board. IMG_20150904_143856That way we don’t have to vapour barrier, and we’ll be adding extra structural integrity to our base. The rigid board is closed cell foam, and it is petroleum based of course, so it is intrinsically very adept at preventing moisture intrusion (and mould development). It’s printed on each board that at least 20% is recycled material, too. Our floor is going to be R-20!! Hooray for warm feet. The roxul won’t go to waste though because we are going to put it in all our walls 🙂

We have an account at the hardware store now, so we’re feeling very professional and important being able to say “Yes, put it on my account, please”! We bought our stack of insulation and the very nice people working in the yard offered to bring it over to our warehouse with their forklift! Gotta love rural Newfoundland. IMG_9276

Each (standard) bay in the trailer frame is 4″ thick, 23 3/4″ long, and 91″ wide. This meant we would get two pieces from each sheet of rigid board, and each bay would accommodate two pieces stacked on top of one another. There are a few exceptions to this, such as in the axle section, and the two end bays, so we adjusted measurements accordingly. We first started out cutting our pieces to size using our circular saw. This achieved very straight lines, and it was ok, but the IMG_20150904_163058blade spins so fast that it actually burns the foam a bit along the cut, and also, I find it a bit overkill / aggressive for this kind of material. The weight of the saw causes the sheet to bow in the centre along the axis where it is being cut, and this sometimes causes the blade to get pinched by the foam, resulting in the saw kicking from time to time. This is not fun. It is a pretty amazing machine though, I enjoyed using it when it was cutting smoothly, and it will be much better when using it on wood.

On day 2 of insulation, Tuesday September 9th, we incurred a power outage for the majority of the day, so we had to try a different method. As it turns out, using a utility knife blade to score the rigid board and snapping it along that cut works beautifully! I’d say even cleaner and faster than the circular saw, and safer as well. We kept this up even when the power came back on. Getting a really snug fit for these pieces of insulation is really important in order to block drafts and to have an efficient and economic subfloor. Why pay for heat if it’s going to escape out through gaps? I took a segmented video laying out the whole process of preparing a sheet of rigid board to place within the trailer frame- you can watch it below!

Using a regular handsaw works well too, and we used one for some of the smaller, thinner trimming we needed to do on certain pieces. And that bread knife… I gotta say, it was essential for those notches. If you’re a good hand at cutting homemade bread, you’ll be great at slicing insulation with the same knife. We finished insulating on September 9th, and bought our stack of 3/4″ 4′ x 8′ tongue and groove plywood for our subfloor as well. We’ll very soon have something to stand on!

Finished job!

Finished job!

The Aluminum Flashing Blues

Exterior Shell, Sub-floor

I’m writing this now after 4 of the toughest days on record of this entire project. I must say, I’m glad I waited until now, because this post would have been steeped in a lot more despair and frustration otherwise, haha. We started on Saturday, August 29th thinking we would do the entire job in one day. Hey, it’s just a bit of aluminum flashing! We said. Roll it out and just pin it on! We thought.

Tim, looking sad, brushing shards of metal out of his hair.

Tim, looking sad, brushing shards of metal out of his hair.

Not so much.

This is an excellent example of where theory and practice do NOT equal each other. However, there is a silver lining (other than the one going in underneath your trailer – hehe). With something extremely challenging such as this comes a great sense of accomplishment, and allows your confidence to grow, even if it’s just a little.

I’m not going to spend too much time on our failures and struggles, because neither of us really want to re-live them, but I’m also not going to sugarcoat this. About half way through this task, I asked a group of fellow tiny housers in desperation whether or not this was the hardest part of the whole build, and a lot of experienced people actually said it was. This gave me a little strength to keep on going, knowing that we weren’t the only ones who struggled, and that it was going to get better!

Flashing the underside of the trailer is an important step in any tiny house build. It ensures that any little critters looking for a home won’t end up sharing yours. Also, since we are insulating the bays in between our trailer joists, it will keep our insulation dry and in place. Lastly, it will deflect road wash and any debris or small rocks from the road when we’re towing our tiny house. We bought the majority of our flashing at Kent, and it came in 2′ wide, 50′ long rolls (we bought 2 rolls). A lot of people use galvanized steel flashing on their tiny house trailers because it’s cheaper, but all we could find was aluminum, so we went with it. Since our trailer cross members/joists are on 2′ centres (that means that from the centre of one joist to the centre of the next is 2 feet), we wouldn’t be able to align our strips of flashing width-wise because proper overlap (at least one inch) wasn’t attainable that way. The only option was to send the strips length-wise. THANKFULLY we had the good judgement from the beginning to not try and do full 28′ long strips… I think we’d have each other murdered by now if we had. We decided to break it up into sections, as per the picture.

Our trailer, broken into sections for flashing installation.

Our trailer, broken into sections for flashing installation.

We started in the red section, progressed to blue, then green, and finally purple. They each had their defining qualities, good and bad. Of course, as with anything you’re doing for the first time, the beginning is kinda ugly, and the end is kinda beautiful. I’m also really glad we chose (not on purpose though) to start at the back, where it is the most straight forward. The process basically dictated that we attach each strip, from left to right, overlapping each one by an inch. The perimeter is attached using wood screws (as it is attached to the wooden side rails), and the field is attached to the 1/4″ steel joists (C-Channel) with 3/4″ self tapping screws. We were able to cut our strips of flashing just using a utility knife against a straight edge. Going over the cut 3  to 4 times and then bending along that line would snap your piece off cleanly.

On deciding how to orient our overlapping edges, it was useful to think about how shingles work. The bottom pieces go on first, and you work your way to the peak of your roof, so that water will be directed down and away. BE the drop of water and imagine where you would go. We decided to have the flashing strips overlap such that at any lengthwise intersection, the left piece was on bottom and the right piece was on top. Since oncoming traffic would direct water towards our trailer from the left hand side (in North America, anyway), it made sense to us to overlap our flashing to protect infiltration from the left. Similarly, since driving would direct any water hitting our trailer from the front to the back, we overlapped the sections such that the front section (green) was underneath the middle section (blue), and the middle section was underneath the back section (red).

The good news is that aluminum flashing is light and flexible, making it easy to manoeuvre. The bad news is that aluminum flashing is light and flexible, making it difficult to get it flat and straight. SIGH. This was our biggest issue overall. I’d almost consider getting a slightly thicker gauge of flashing if I were to do it again, just so it would stay a little more rigid when installing. In the beginning, we were trying to hold IMG_20150829_144149up the strips of flashing using our hands and a few clamps along the edge. We also tried milk crates as stands, but they weren’t tall enough. These methods didn’t last, since only two of our clamps are really any good, and we just couldn’t get the sheets uniformly tight enough to the underside of the trailer this way. We did this for a whole day though, and then spent the better part of the next day re-doing it all. Every time we would drive a screw, the aluminum sheet would buckle slightly, in one direction or the other, creating dips and bows along the length and width of the piece we were working with. It was maddening. At last, we found the silver bullet, using long, narrow pieces of wood under the two adjacent sheets being worked with, along their centres, clamped at either end using a metal C-clamp OR a scissor jack.

Loosening your clamps a touch allows you to wiggle the sheets into place so that they’re square, flat, and properly overlapped. When they’re perfectly in place, tighten, and then you’re ready to roll around on the floor on a sheet of cardboard for a while. Drilling the pilot holes and driving screws into steel from UNDERNEATH the trailer was pretty miserable. To make it worse, every hole that was drilled spouted hot, sharp, metal filings that would rain down on your face, neck, arms, and into your shirt. Blissful. We’re going to be finding these little bits for days I think, in our clothes, in the bathroom, the kitchen.. everywhere. They grab onto your hair and your clothes, even after having been washed!

Up until now, I haven’t truly hesitated with anything connected to the building process of our tiny house; we’ve split everything 50/50. But once Tim was nearing the halfway mark, I will admit, I was questioning my capabilities and a little doubt snuck in. It was day three of this task, we had been working long days, often as late as 1:30am, and we had only just started to yield a little success with it all. I’m going to be honest, doing this kind of stuff tests you. It will test your relationship with your partner, your ability to stay positive, to be kind, to communicate effectively. Especially when one role of a task is significantly more demanding, both physically and mentally, than the other role. The person underneath the trailer driving screws can’t really see the steel joists that well, or the degree to which the flashing is buckling, so constant discussion and trouble shooting amongst each other is required. When my turn came, I was determined, but I did need a bit of a pep talk, and Tim did a great job 🙂 I’m psyched to say that I basically did the entire front end of the trailer: the green and purple sections.

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The purple section probably took just as long as the green section, just because it was so time consuming to think through all the shapes and angle translations required to

Step 1 - Check it out and take your measurements

Step 1 – Check it out and take your measurements

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Pieces that fit in around the tongue

fill in the spaces around the trailer tongue. It was also tricky accommodating the 4 hangers we installed on the corners for our scissor jacks, and the 6 hangers within the axle section. Measure twice, cut once, people!!

If you do cut a bit too much off, or you have any kind of gap, it isn’t the end of the world though. It can always be patched, or filled in with caulking, or even taped over with aluminum foil duct tape.

Step 2 - Trace out your cuts on to your sheet with a sharpie.

Step 2 – Trace out your cuts on to your sheet with a sharpie.

Also, a sharpie is perfect for drawing lines on aluminum.. just hard to keep the felt tip clean is all.

Step 3 - Make your cut!

Step 3 – Make your cut!

It kinda felt like a big arts and crafts project towards the end, and we really started gaining fluidity and momentum. By the end of it, we were feeling pretty good about it all, and it seems as though we have succeeded in protecting our investment from underneath. I might even go so far as to say I’d do it again… but maybe that’s the elation of being done talking. Here’s a few pictures we took on Day 4 of the finished product (Tuesday, September 1st).

Part of the green section

Part of the green section

Looking towards the back, from the tongue..

Looking towards the back, from the tongue..

Suggestions for anyone doing this themselves in the future:

  • Invest in an automotive ‘creeper’ (like a skateboard) so you can roll on wheels and not your back.
  • Make sure you have a combination square, a carpenter’s square, a utility knife, a measuring tape, large metal c-clamps and scissor jacks, a few 10′ – 12′ lengths of 2″ x 4″ or 2″ x 6″ wood (for bracing), and needle nose pliers. Of course the screws, drill bits, drill and driver go without saying.
  • If you have the means to flip your trailer over so that you can have gravity on your side when installing the flashing, DO IT!
  • Give yourself a break. This is hard work, and you will get through it in your own way, in your own time. Don’t rush it, because you will probably get even more frustrated and potentially end up wasting material.

Sub-floor Prep

Exterior Shell, Sub-floor

Now that the trailer has been completed, we have started what we’ve been fondly referring to as “The Real Build”. The anticipation to start working with wood has been high, and we got our first taste of it on Friday, August 28th. It took us nearly 9 hours to install the wooden rails around the outside perimeter of the main frame of the trailer. These rails will provide a nailing surface for our plywood sub-floor and the bottom plates of our studs. IMG_20150828_153023I have to say, it was really enjoyable! Wood is a DREAM to work with compared to metal. Even though we were still attaching wood to metal, it was the wood that we were manipulating and levelling, and what a difference!!!

The first thing we did was spend about 10 minutes levelling the trailer from all four corners using our 2-ton scissor jacks, and then we were ready to get at it. We used 2″ self-tapping screws to go through the 1.5″ of wood and 1/4″ of steel, and staggered each screw 1′ apart along the length of each piece of wood. Alternating our screws from a higher position to a lower position, with respect to the centre line of the wood, prevented the creation of a single axis of screws along which the wood could curl and potentially crack, over time. IMG_20150828_183357Our purchased plans said to place screws every 2′, but this didn’t seem sturdy enough to us, so we went with the 1′ intervals. The imperial system is still driving me nuts, but on top of that, I find it so irritating how the measurements of wood are not even true to their imperial names. 2″ x 4″ wood in reality is actually only 1.5″ x 3.5″. AND, any given piece of so-called 2″ x 4″ has a better chance of spouting maple syrup than it does being actually straight! Rant over….

It wasn’t in the plans we bought, but it was mentioned to us that it might be wise to use a cushioning / water barrier material between the wood side rails and the metal of the trailer frame, as well as when we’re laying down the plywood sub-floor. I brought this query to the awesome facebook group “Tiny House People”, where I got a resounding “Yes!” to this question. So glad that we decided to do this. I’ve already complained about how wood isn’t straight, but we didn’t really take into account the fact that even though our metal should theoretically be flat, after painting, the surface was a little uneven due to drops of paint having dripped down and hardening into little convex ridges here and there. We picked up a roll (in the range of 80′) of 6″ sill gasket, and wrapped it around the entire exterior perimeter of the trailer frame in one continuous piece, sandwiching it with our 2″ x 4″ wood rails as we went. It filled any gaps between the two materials, creating a nice tight seal. This stuff is basically composed of a squishy, white, open cell foam sheet.
IMG_20150828_142002

Before we could start attaching anything, Tim notched out cylinder shaped channels in the wood where it would line up with our welded-on threaded rod. We didn’t really have the right tool for the job… I think a router would have worked well. But we had a grinder, so Tim marked lines showing the needed width of the grooves and just ground out the wood with a wheel on his grinder. Not perfect, but it worked.

C-clamps are now my very best friends. They are amazing. If there’s a bow in your wood, or it’s twisted in any way, they are there to reduce the amount of profanities used and make your life generally easier. Self-tapping screws however… we’re not as good friends. I’ve heard you can buy ones that actually work, but ours were a big sham. Somehow, the very first one went in ok, but after that they kept breaking so we had to drill pilot holes.

We bought a box of 100 screws, and ended up having 5 left over. Sunk a few additional screws around the pieces of welded-on threaded rod, to bring the wood as tight as we could around those, as well as any other places that needed a little extra coaxing to be tight and straight.

In addition, we made the realization that our trailer is actually about 3/4″ longer than expected! We measured everything and it turns out that the 24′ pieces of HSS from the mill were slightly longer than spec. Never even considered that could be possible! Haha. The wooden 2″ x 4″s come in 10′ and 8′ lengths, so we needed two 10s and an 8 to flank each side of the trailer entirely. With the newly discovered discrepancy, this meant we had a little 3/4 inch gap between the tail piece and each side rail. To accommodate, we cut two small blocks and hammered them down into each gap and screwed them in from the end. No biggie.

I feel terrible writing about all of this next bit, it will be such dull reading. But, I’m afraid if I don’t write it down, I will forget the small details if we do this all again someday. If you’re curious about the specifics, read on! If not, stop here 🙂

 


 

The process of sinking each screw went a little like this:

  1. Place the sill gasket against the metal trailer frame with left hand, then hold the 2″ x 4″ wood against the sill gasket with right hand. Tighten clamp around the whole thing. Your partner does the same thing at the other end.
  2. Take a measuring tape and stretch it the length of your 2″ x 4″. Mark a vertical line with a pencil at each 12″ interval, making sure to have the two end screws 2″ in from the edge of the wood, regardless of where the nearest 12″ interval lies. Mark a horizontal line at each interval, 1″ down from the top or 1″ up from the bottom, alternating, creating a zig-zag pattern. The intersection of the lines at each position will be the home for each screw.
  3. Make sure the top of 2″ x 4″ is flush with the top of the metal using a combination square and a level, so that the plywood sub-floor will lay flat across them both.
  4. If the situation isn’t level, use a rubber mallet to hammer up or down on the wood, whichever is necessary, on the outside of the clamp. Doing this allows small increments of change in the position of the wood, all the while keeping it snugly in place thanks to the clamp.
  5. Drill a little piece out using a 1/2″ drill bit, to a depth of about 1/8″ to 1/4″, giving a space to counter sink the screw head. This way, the heads of the screws won’t be poking out making it impossible to get our sheathing and siding flat against this wood down the road. Pro tip: wrap some painter’s tape around the tip of the bit, making an edge so you know exactly how deep to go when drilling. Don’t want to make these too deep.
  6. Drill a pilot hole through both the wood and the metal so that your “self-tapping screws” (i’m convinced this concept is a sham) will go through without getting worn down or snapping off. We used #10 screws, which have a shank diameter of somewhere around 13/64″ (imperial, whyyy???) so we needed the pilot hole to be smaller than this. I think it was something like 9/64″.
  7. Sink your screw, at last. Move clamp further down the line.
  8. Repeat