Yay, Summer! And An EPDM Roof Update.

 

I had such a simple plan in mind.  Some dimensional lumber trusses laid straight across the top plates, covered with simple panels of plywood, followed by simple panels of rigid insulation, and covering that in turn with a single sheet of EPDM.  I thought I was prepared with the proper adhesive, plenty of fanfolded insulation, the proper nails and screws, all that.  I was wrong.

This would be a good place to make a sandwich to eat while reading.  It’s a longish post.

First, of course, there is the extra layers I’ve already added, that make up the insulation sandwich.  They are really important to break thermal bridging, but add expense, labor and height.  Next, it turns out the fanfolded insulation I have “might” not be the correct kind for my brand of EPDM (it’s hard to know for sure because my manufacturer has been absorbed by Firestone, and their requirements “might” be different ~ it’s common with EPDM manufacturers to each have very narrow and specific needs for each brand).  The safest route is to use 6 inches of polyisocyanurate insulation on top of the roof deck, and fully adhere the rubber layer on top of that.  Uh, oh, I don’t have 6 inches extra height to spare.  Plus, that’s OMG expensive.  I’m feeling a little panicky now.

After much investigation, it seems most brands of EPDM can be applied directly to wood, but only smooth-as-silk wood like Fiberboard, which is a very bad product to use in this wet environment.  So add more hours of investigation.  It looks like silicone is compatible, and can (probably even should) be used to fill all holes, gaps and cracks larger than 1/4 inch in the plywood decking I have to create a smooth surface.  So, off I go to buy silicone.  Not the mixed stuff, only pure silicone, since I couldn’t find evidence confirming the compatibility of the mixed stuff with EPDM.  So I buy several contractor tubes of silicone and a spatula thing to smoosh the stuff into crevices.   FINALLY, ready!

Maybe.

Oops, no.  Any and all splinters or rough bits need to be sanded off or there’s a risk of the rubber tearing.   Fine.  I do some research and buy a powered sander.  Hand sanding will take forever, and sunny days are rare and precious here.  I’ll need to sand the barn wood interior anyway, so this extra purchase doesn’t dismay me, not too much.

At this point things get fuzzy.  I literally can’t remember why exactly I deemed it necessary to purchase a gallon of liquid EPDM,  I really can’t…somewhere in here my doctors changed my meds and I sleep-walked through a couple weeks.  But I bought the stuff and am going to brush it onto all the plywood edges for waterproofing and over the clips to soften their sharp edges.

Somehow I’ve gone far astray from my “simple” roof solution!  Tomorrow is supposed to start a week of dry sunshine, all my newly purchased stuff has arrived, and my knee is down to a dull ache.  My plan is to sand, sweep and silicone.  I have no idea how long it will take, but hopefully not more than a day or two.  Fingers crossed!

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In case of fire, exit building before tweeting about it.

Taking a cue from Macy over at minimotives, I’ve decided to write about safety in a Tiny Home. People ask me about it when they find out about my build, and I’ve seen lots of questions in various blog’s comments. Although my Oliver’s Nest isn’t livable yet, I feel entitled to address this issue, as I live in a (even Tinier) truck camper while building her.

So. first off, privacy. It’s related to safety, if you think about it. Who feels safe with no place to get away from everything? To hide? To really relax? I can only do what most people do, close curtains and lock the door. Here in this camper though, those normal things doesn’t really cut it. The walls are thin, so sound carries both inwards and outwards too clearly. The windows are single pane, and some of them won’t seal close. When the wind gets to really gusting, the whole place jerks sideways with a booming sound, and if there’s an electrical storm nearby, I get to feeling a bit tense with those sound effects!

Oliver’s Nest, on the other hand, will have 6 inches of insulation in the walls and floors, and over 7 inches in the roof. I’m positive that sound will be damped by the thick sheep wool insulation. The whole structure is heavy, and sits solidly on blocks. The double-paned windows aren’t installed yet, but no doubt will be more effective than the campers are. During strong winds she doesn’t even creak. Wind and storms be damned in there!

House fires. That’s a scary one. Although I haven’t read of any fires in a Tiny Home, even those with wood stoves, odds are someone will have to contend with one at some point. I’m doing my best to ensure it isn’t me. In such a small home, even a small fire could render it unlivable. It’s taken a lot of thought on where exactly to locate the wood stove so that I can make the minimum recommended clearances on both it and the chimney. The insulation behind the stove and chimney will be Roxul (rock wool) which is completely non-flammable. I’ll have the required heat shield with an inch of air space to the wall. I’ve discovered pretty chimney guards to help prevent contact burns. I’ve thought about the weight (and my home is already quite heavy), and have decided to place it over the axles. Interior gravity-fed water storage tanks will be located nearby (overhead, in the loft) for additional insurance against disaster. Lastly, I have a plan in mind for a metal roof to be added after Oliver’s Nest is moved to her permanent location, to cover the EPDM.

And what about scary events like forest fires, or random disasters like the girl who lost her newly-built Tiny Home to a barn fire? Once again, such small homes can be quickly ruined. How to best prevent these things from happening? I’ve already spoken to one of the forest rangers local to my property to find out what they suggest for protection. It was a surprisingly reassuring conversation, given the history of severe forest fires in the area. He gave me great advice and I’m a bit less worried, as I know now how to best protect my home. I can only hope everyone is also careful, no matter the size of their home.

Moisture, as I’ve said about a million times, is a real problem here in the Pacific Northwest. It’s imperative that any home in this area be built to withstand water intrusion from every angle. This comes under Safety, as mold, mildew, rot and their attendant pests are not safe or healthy to have in your living space. If the rot gets bad enough, you can end up with not much of a home at all.

On to the question of having my home towed away or broken into. Honestly? I think it’s a valid concern. There are uncool people in the world who think nothing of taking what they want, and messing with what’s left. The good folk over at Solar Burrito Blog had stuff stolen from their building site while they were away, and that can happen to anyone, especially those with an attractive target like a Tiny Home in a more rural setting. I’m not worried too much while living here, as there are three large dogs, lots of neighbors, and my home doesn’t show from the road. There’s also the old tires on the trailer….replacing them will be an unavoidable expense, but for now helps keep my home safe. I will be removing the wheels once on my own place, which only solves part of the problem. Keeping a safe home in a very rural place isn’t just a worry for Tiny Housers. I have to hope that strong fences, big dogs, a low-profile, and knowing how to use a gun (with appropriate scary signs) will keep me safe from all sorts of predators.

One last safety feature I feel strongly about: having two methods of emergency egress. Some people make do with windows for an emergency exit. Some apparently don’t allow for emergencies at all, from looking at their tiny little windows. I have two doors (not yet installed) on opposite ends of my home. I made the trade-off of useful interior wall space for safety. It has made planning out the interior much harder ~ I admit to working out plans with only the one door, which allowed for more counter space in the kitchen, or a fully enclosed bathroom, or a much larger closet ~ but kept coming back to wanting quick access to the outdoors. So, one end of Oliver’s Nest will have a full wall of windows due to the french doors that I’ll be able to open out wide onto a large, covered patio area. The other end will have a dutch door with a window in the top half. This door will open inwards (in the event of deep snow), let in more light, and give me quick access to the “mud room” area of my little home. I feel good about my design.

I’m really curious about how other people feel about these subjects. Please feel free to comment on your own thoughts and solutions!

As for roof progress?  Not nearly as much as I thought there would be.  I was so wrong about being nearly ready to install the drip edge.  So terribly, terribly wrong….  I’ll update soon. 🙂

I. Am. Exhausted.

Putting a roof on is so much work!

The sun glinting off the newly-fastened trusses is rewarding

The sun glinting off the newly-fastened trusses is rewarding

First, all the decisions to make: roof style (gable, gambrel, arched, flat?), whether or not to put in dormers (light and precious, precious space added, depending on what roof style), how much insulation, what type of insulation? What material for the outer skin? Metal? Asphalt shingles? Wood shakes? EPDM? hot or cold (vented) roof? I will use a wood stove, so chimney through the roof or through the wall?  Good thing I like to do research.  There are so many choices, so much information to evaluate!

Insulation going in as each truss is attached.

Insulation going in as each truss is attached.

Then comes the reality of putting that puppy together.  I find that this is the stage where flaws in my design really show up, necessitating on-the-fly changes and re-evaluations of my patience and ability.  I’m sure that with generous helpings of both, I could have fixed the initial roof trusses, but after staring at the darn things for a year, decided I lacked both.  Off with the cool gambrel trusses, and on with the “flat” roof.  Boring, yes, but also doable and gives a huge bang of space for the buck.   Even so, this is a lot of work.  Hard, sweaty, muscle-groaning work.  I never knew that sweat actually DOES sting your eyes until I started this project.  Maybe it’s partly due to my state of physical fitness (almost nonexistent), but more likely it just comes with the job.  I am handling heavy, awkward pieces of wood, really high in the air, alone, and without experience.  Yeah, I sweat!

Sweaty, frizzy, and dirty.  I'm quite a sight after a day up there in the sun

Sweaty, frizzy, and dirty. I’m quite a sight after a day up there in the sun

There are days when I’m tempted to just build a most basic box, and not worry about boring stuff like thermal bridging and moisture problems; or simply follow a plan developed by someone other than me… I can see the allure. Well, actually seeing as it’s me talking here, the truth is I like a challenge, and to try to do things as “right” and “perfect” as possible. In my own special way. In my own, special, really hard-to-do way.

The saggy middle portion of the roof makes the insulation look too skimpy.  After I go below and screw the lower sheathing to the trusses, the insulation looked much more impressive

The saggy middle portion of the roof makes the insulation look too skimpy there. After I go below and screw the lower sheathing to the trusses, the insulation looks much more impressive, but I forgot to take a photo

So. What stage is Oliver’s Nest at?  Well, the insulation “sandwich” layer is on, the trusses have been wrangled into place and tethered down by many screws and metal tie-downs, the Roxul insulation is tucked in and securely covered by the AtticFoil radiant barrier, and the sheathing has been cut to size and numbered so I will know which piece goes where without (hopefully) any mistakes. I would have liked to use full-size plywood pieces, but they are just too heavy and unwieldy for me. I don’t think even having my boy over to help would get them up. I don’t think it’s the strongest roof design, but it will work for now.

My 22 foot piece of AtticFoil, rolled up as neatly as I could, ready to be carried up to the roof top and placed over the Roxul

My 22 foot piece of AtticFoil, rolled up as neatly as I could, ready to be carried up to the roof top and placed over the Roxul

I lay the foil lengthwise along one half of the roof, stapling each side to ensure air can flow from side to side (Cold Roof style)

I lay the foil lengthwise along one half of the roof, stapling each side to ensure air can flow from side to side (Cold Roof style).  The foil will also make sure the insulation stays put, and might even add to the total insulative value

I want to  remember how much I messed up my knee doing this and yet continued on;  how sore my shoulders and back are.  Years from now I want to appreciate the work I’m putting into this little home. I often downplay accomplishments, and I’d rather not do that with Oliver’s Nest.  It is an important part of a giant leap-of -faith that I can make a happy life for myself, and hopefully leave a lovely space for my son some day.

Finally, something the closely resembles a roof! My water bottle rolled right off the edge to bounce on the gravel below, so I know there's a little slope ~ yay!

Finally, something the closely resembles a roof! My water bottle rolled right off the edge to bounce on the gravel below, so I know there’s a little slope ~ yay!

Edge Clips are helpful to beef up strength, and to guarantee perfect spacing

Edge Clips are helpful to beef up strength, and to guarantee perfect spacing

 

After having to balance on loose trusses for days, being able to walk across the roof deck is wonderful!  I’m thinking it’ll take another day to finish the decking, and after that a day to get the drip edges on.  It’s supposed to be drizzly for almost a week starting tomorrow, so my knee will get that rest the doctor ordered.  Booo-ring!

Up On The Rooo-ooofff…

The roof is going up!   A little later than planned, but weather and finances, health and mood all have to come together in a perfect storm.   It’s OK though, because I spent the time re-thinking (for approximately the thousandth time) how I wanted the roof to come together.   And of course I changed my mind…again!   Actually, I didn’t so much change my mind, as recall a method of insulating my flat roof that I’d run across more than a year ago.   So glad I came found it again!  This is the illustration from the website Building Science Information:

Breaking the thermal bridge

Basically, you build a thermal break into the roof with an extra layer of exterior grade plywood over a layer of rigid foam insulation.   You can’t use OSB, which can’t handle moisture or breathe ~ it has to be plywood.   One of the local lumber yards sells what they call “utility” grade 3/8” sheets for only $10, which I feel is fine for this purpose.   The more (thicker) insulation you use, the better ~ I used 1 1/2 inch expanded foam.   I really wanted to use extruded foam, but it’s out of my financial reach.   This extra layer goes up before the trusses, and creates a thermal break, making the insulation laid between the trusses more effective.   It adds to the total R-Value, as well.

An important step is to keep interior moisture from getting into the foam, so having a vapor barrier between the rigid insulation and the interior air is vital.   On the other hand, it’s also vital to allow any moisture that does get into the foam or wood an easy path back to the outdoors.   Good ventilation combined with keeping rain out is key here.   I’ve purchased perforated foil radiant barrier to ensure air flow, and will keep wind and wind-blown rain out of the roof with a good-sized overhang and deep fascia.  The point of the foil is to keep insulation fluff in place, while still allowing it to breathe with the perforations.  I’m using this stuff:

perforated radiant barrier foil watermarked

48 inches wide so easy-peasy to install

 

There are products made specifically to create air channels, too, called Attic Vents or something similar.  Some I’ve seen are made out of cardboard ~ easy to DIY.

 

Here’s a simplified list of the roof layers:

Ceiling treatment ~ in my case, I’ll use painted barn boards.

Vapor barrier of visqueen/thick plastic sheeting

3/8 inch CDX plywood

1 1/2 inch rigid foam board (R-Value 7.5)

3/8” CDX plywood

2×8 trusses filled with 5 1/2″ Roxul (23 R-Value)

ROXUL COMFORTBATT

Almost as good as sheep wool, and more familiar to any inspectors who nose around once I’m on my property.

Perforated radiant barrier

23/32” CDX plywood sheathing, with the gaps filled with a flexible sealant

.60” thick EPDM from Gentite fully adhered to the sheathing

10 by 25 feet ~ no seams!

 

I am pretty sure I have linked to this site before, but it’s so full of good information that I’m going to do it again.  You can get lost in there, digging ever deeper in technical building goodness.  Anyone thinking of constructing a building should check out the Documents section, even if it’s not a DIY.

UPDATE: I started writing out this blog entry on June 2nd, and didn’t get around to finishing up that day.  Now, a couple days later, I am embarrassed to say that I’ve managed to injure myself (again).  I’d like to pretend it hasn’t happened, but this is a record of my experience building my own home.  And part of that experience is the occasional (I HOPE it is only occasional) booboo.  Soooo, this time I jacked up my right knee pretty well.  It’s actually kind of amusing, as I first hurt this knee way back a couple years ago when I was first starting out on the build, by tearing the meniscus.  A few shots of cortisone, several weeks in a brace, and many painful months later I could walk without a limp.  But the dratted thing locks up multiple times daily, and on Saturday morning it locked up while my hands were full of plywood, causing me to force it straight instead of babying it out ~ ow!  Then, a few minutes later, I dropped that same sheet of plywood (on edge) onto that knee.  Swearing ensued.  THEN, and I’m still not clear how I managed to do this, I hyper-extended the SAME KNEE with my full weight plus (you got it) a sheet of plywood TWICE, and felt something finally give in the back. OMG OUCH!!!

Yeah. Don’t work alone with heavy stuff if you can help it, and always make safety your highest priority.  Trying to get the roof on in dry weather, meaning fast, caused me to do several clumsy things, and now I’m in a sort of removable cast to keep the knee immobile, and supposed to stay off the leg entirely.  Probably won’t happen, as I still need to get the roof on before it rains again.  We’ll see.

Here’s some pictures of what I gotten done so far:

1/4 inch sheets of plywood are hard to manage when you're short and out of shape

1/4 inch sheets of plywood are hard to manage when you’re short and out of shape

I painted these sheets top, bottom and sides because I wasn’t sure if they are CDX.

 

Laying out the rigid insulation

Rigid insulation

Starting to frame in the rigid insulation “sandwich” layer.

 

Covering the foam with thin CDX plywood

Covering the foam with thin CDX plywood.

This is still pre-knee destruction.  Look at the cool camo paint, heh.

 

This is some of the pile I schlepped back and forth on the roof

This is some of the pile I schlepped back and forth on the roof.

My son came over early Saturday morning to hoist a bunch of heavy/bulky stuff up to the roof for me.  I really wanted to do this whole house by myself, but I simply could not get these heavy things up there.  Of course, this meant I had to repeatedly move a big pile of (heavy!/bulky!) stuff around, trying to keep it out of the way.   Great workout.  At this point I’ve already done some of the knee damage, but the hurt hasn’t truly hit yet.

 

Trusses laid out, before cutting them into the right shape

Thermal break put in, and more room to work in!  Trusses laid out, before cutting them into the right shape.

My 2×8 trusses measure out to literally 7 inches, not 7 1/2 like I expected.  This meant I could only use 5 1/2 inch insulation batts instead of the 7 1/2 inch I originally planned on because  I want a good inch and a half of air between the Roxul and the sheathing.  I purchased the planks from two different lumberyards, so I guess it’s just lumber math?  Heh, or instead insert men measuring joke here.  So now I’m only getting an R-Value of 23 between the trusses, instead of 30.

 

Waste, but not too bad.

Waste, but not too bad.

The middle of the trusses are left at the full 7 inches, and are cut down to 6 inches at the ends.  Not quite as much of an angle as I wanted, but there’s that whole “7” instead of “8” inches thing again.

 

All washed up and ready to be cut to size.

All washed up and ready to be cut to size.

Part of my huge pile of wood pulled out to use for the flying rafters and barge boards.  I had to scrub a couple years worth of dirt off of them, due to losing the pile in canary grass.  That stuff grows to over 6 feet here!  Not my fault for piling it in the pasture, nope!

 

DIY bird blocks to ensure great air flow and hopefully no bugs.

DIY bird blocks to ensure great air flow and hopefully no bugs.

Bird blocks are those wood pieces with holes covered by mesh you find up under the eaves.  From the research I did, the holes don’t offer enough air flow in most cases, so I made these.  The mesh I used is 1/8th inch to deter insects stapled to 2x4s.  These will be obscured by the deep fascia boards I plan, which in theory should keep rain and direct wind out of the roof interior.

That’s all for now!