Also should mention that there will be 3.5" of closed cell spray foam on the underside of the roof.

 

I like a cover board between osb and plywood. The rest sounds fine. I typically don’t see any type of seam roll on epdm.


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Cheap insurance

Also I prefer to cut the edge flush as it makes the drip application much cleaner. Also the only place I ever caulk is where my coverstrip overlaps, just a little dab in the corner.

 

Skip the sanding and put down a layer of IOS or at the very least celotex

 

Sanding would probably take about an hour....just to knock down any area where the nail left any splinters. I'll try....but not sure i can get ISO (?) or celotex.

 

Very interesting skewed roof, wonder if there will be issues because of it? I really like the design, so innovative and looks good also!

 

Thanks.....Good question....we shall see....lol. For application of EPDM- the 'only' issue I can see would be trying to lay larger sheets on the roof to glue together? Because of the skew....

 

Well, I'm sure in Canada you can get iso board. A coverboard of some sorts over the sheeting and under the membrane is the cheapest insurance you can get. Also adds to your insulation value

 

The insurance would be if the EPDM had to be ever removed? And the smoother surface itself? I'm above the required R value for roof insulation. Would the roof require a nailer board around the perimeter, next to the fiberboard? For a more solid edge to nail the top of the drip edge to.

 

Unsur ance against a spli.ter poking a small hole in the membrane of a faster backing out and puncturing it. I wouldn't sweat a nailer board, just make sure you use a long enough fastener to grab and hold the framing. Either a 3" roofing nail (ring shank if you can find it) or a flat roof screw with no plate and you will be fine

 

Thickness of fiberboard? Also...how many mechanical fasteners per 2x8 sheet? Thanks...

 

...

 

Very cool design but looks like a nightmare with sealing, insulation, and upkeep.

Emily
http://roofingrenonv.net/

 

Do explain.....

 

I figured you would find it. If they sell epdm, they sell the fiberboard. Glad you're going with it. I've seen it done, glued directly to the sheeting, but not by anyone who actually does roofs.

Look at the installation instructions for the epdm. There is a specific pattern for the fasteners, for the fiberboard. It doesn't take too many. Need to screw it down and use the 3" deck plates.

For your pipe flashing, just use a standard epdm flashing. They use a stainless steel worm clamp to hold to the pipe. No sealant needed.

For the perimeter, I realize you are going for a particular look. If it were my roofing project, I would run the epdm over, on to the fascia, screw on the termination bar, run a bead of lap sealant on the top edge, and be done.
Of course I get the impression you don't want the look of that edge.

The design is great. I really like the look.

 

Actually..... it was the local building supply company that had the donnacona in stock, the roofing supply company had no clue...lol At 20 bucks a sheet......another 400+ bucks....ouch. If I knew the cost of the tape the covers the drip edge...I probably would of gone that route you suggested........$900 for two 100 ft rolls. Thing is....I need just over 100ft....lol On a good note....the snow has arrived. I can now remove the spark arrester I made for the stove pipe, being only 1/8 inch mesh it would plug up in less than 3 days. Note- I added another 2ft section of pipe after pic was taken.

 

Very nice, I like it. Sorry if I missed it but how are you finishing the interior?

 

Thanks.....well I'm gonna go with a monochromatic theme. I'm having about 85' of false (perimeter of ceiling) beams milled in the next few days....either fir or pine which will be stained dark in color, then some poly added. The ceiling will be gyprocked/painted then finished with 1 1/2" x 1/2" x 11' stained slats/trim, either at 16" or 32" centers to accentuate the 'movement' of the ceiling. White laminate in kitchen with doors and drawers banded with dark stained birch. Lots of smaller windows. On demand propane hot water (installed). 100 amp elec panel (installed). Grey vinyl barn board flooring from Home Depot.....very nice stuff. Lots of wood trim and utility art....which I sell. Will be designing an entry door similar to this one that was in a cabin that I built and just sold....

 

Bathroom will have a look similar to this.....tub should be arriving shortly....

 

Hi guys....and girls...

Designed a tiny home with a slightly different roof line and have a couple of questions on the install. I'm using 60 mil Carlisle EPDM.....unfortunately I couldn't get anything wider then 10ft, so they'll be 4 seams and the first one will be centered at the middle of the 14'x40' home and working out each way from there. Roof has 7/16 OSB (rough side up) with rafters at 16" centers. I'll go over the roof deck with some 100 grit and soften any burs etc. before I lay the EPDM. Was thinking of wrapping the EPDM over the edges about 3" and fasten with roofing nails, possibly put a bead of lap sealant and or between the EPDM and wood 2x10 facia..(?), where the nails will penetrate. Place brown aluminum drip edge (2 1/2" (top) x 1 3/4" (hangs down facia)) on roof and securing with ring shanked nails/roofing nails(?) and finish with the Carlisle 6" overlayment strip. Cut EPDM flush with the bottom of the drip edge. 10" metal facia will be stuffed up between the membrane and drip edge.....caulked where the drip edge meets the facia if need be. Alls seams with have the 6" Carlisle Securtape. Most likely use 2 coats of bonding adhesive for maximum adhesion on the OSB. Does this sound OK relative to the design of the roof? Do i need termination bars? Assuming I need 1/8" gaps between the 4x8 sheets of OSB. Also....I'm putting a low slope wood stove flashing on the roof (stove pipe will have a spark arrester) and not quite sure how to seal it....being galvanized steel and all. And......Being that the trailing edge changes to a leading edge on the same side of the roof...should I be using any lap sealant on the edge/corner of the roof.......where the EPdM stops?
Ends of roof are a 2/12 pitch (opposite to each other) and rises and falls 3/4" per foot, flat in the very center.

Thanks.

Where oh where do i begin?

Do u really think youre going to get 3" iso board to lay down on that deck and look good? And technically youd have to go with 3.5 or 4" now due to the change in code.

With an epdm roof id go with 5 inches cuz its going to be a frecking sauna in there.

U can get tapered iso board you know.

Btw Sanding the deck? Totally unnecessary. If a splinter could pierce the material, id be really uncomfortable with using it as a roof on my house. Have you ever seen/felt .060 mil?

The overhang and drip edge on top with roofing nails to secure?
Gawd please.. 1st metal isnt super forgiving. Especially L shaped metal. So whatever edge metal you do use, you probably need to get custom fit. And it will never go over the 3 inch overhang. That is typically an application done on a parapet wall when a cap goes over the top and can pin down the material on both sides. Then another cap goes on top of that or the seams are covered by another layer of metal.

Nails on fascia side? Negative
Cut edge sealant is not used as water cut off. Totally different product totally different uses.

Water cut off is used with termination bar when the membrane is stopped on the inside of a parapet wall going up the wall. Between the material and substrate with termination bar pressing that bead of sealant against the material and wall. Hence the name, water cut off. It needs to have direct and constant pressure in order to be effective. Its not caulk. It is hella messy and will get all over everything and everyone and youll never get it off of you or the roof. use with caution.

There is tpo coated metal, which you would use to attach tpo membrane (what you should be using) to the drip edge. You weld it like its a seam. The coated metal is flexible and you can fabricate whatever flashing you need on the roof with it. Use cut edge sealant on the edges of the material that you cut.

Use seam tape or cover strip if you want but really if you install it correctly thats unnecessary.

Id skip both of those tapes and use eternobond if i were to use anything at all. Make sure u prime first.

Youre going to need to start from the ends and the last piece you lay goes in the middle you know? That way the water rolls over the laps instead of into the lap.

Gluing it down? Mehh. Glue is a pita if you ask me but i suppose its a necessary evil on this roof.

Cool design btw. Im curious how its going to shed water and how youd gutter it.

 

If you are already above the r value for insulation then your best bet is not to use a coverboard at all. Just go directly to the deck. The coverboard is softer than the wood and the softer the backing, the easier it is for something to puncture the rubber. I give my customers this example... imagine holding up a sheet of paper. If I throw a rock at it, do you think my rock would go through the paper?

Now imagine holding up a sheet of paper with plywood behind it. If I threw a rock do you think my rock would go through the paper?

The harder the backing the more resistant the membrane becomes.

Iso board is only necessary if you dont insulate the attic. Or if there is no way to insulate under the decking. Blackboard... provides like .6 of an r value so I suppose its used to eliminate the possible friction.

But I promise you a splinter is not going to penetrate 60 mil. And the larger the splinter the less likely it is to pierce the membrane. Plus you are gluing it down so theres not going to be a whole lot of friction. Imo you are going to hate yourself when its time to glue that sucker down.

But let me back up... most everything ive said ive been thinking tpo and this is epdm.. but still pretty much the same thing

And

 

I probably missed a few posts. You are talking about insulation. When I suggested the fiberboard, it doesn't insulate.

You were talking about throwing rocks at paper. The board I'm talking about is not soft. It's hard. Not as hard as osb or plywood, but firm. Actually makes it easy to find leaks. If there is a leak somewhere, you can tap the roof deck. If it's hard, no leak. If it is soft, there is a leak, in the area. The board will soak up water like a sponge.

I think I've glued down every single epdm roof I 've done. Not bad, once you get the hang of it.

I also recommend people have their roof checked every 5 years. Contraction and expansion is tough on epdm. seams always get hit the hardest. I've also seen alot of contraction, but then it doesn't expand back to it's original size. I will see corners that the rubber has lifted off the deck and is spanning an area. I usually blame this on people letting it get too hot. I've seen many roofers say they need to lay out the rubber to let it "relax." What they are actually doing is letting the sun expand the rubber. Then they glue it down. As soon as it cools, it starts contracting. You can't notice anything for a few years, then it's obvious.

This guy is getting plenty of bang for his buck. He's gotten alot of input.

 

on second look, those roof edges arent at all as bendy as I imagined. edge metal will fit fine on that.

 

Ya...in 10ft of roof line the pitch only changes from 2/12 to 1/12. The length (39') of the roof rises 3/4" per ft.....whereas the width (14') is a 2/12 pitch......2" per ft.

 

that water cut will follow you home for miles if your not careful.lol. Messy is an understatement !!

 

Well as long as the project is on hold for weather let me put my $.02 in.

I'd mechanically fasten a 1/4" dens deck prime cover board on the osb deck, 12 fasteners per 4'x8' board. Then Fully adhere the EPDM to the Dens Deck prime.

Why?
The osb is porous and will soak up the adhesive creating a weaker bond. You said you will use a double application of bonding adhesive. BAD idea. 2 reasons, 1. very difficult to apply a second layer of adhesive over another and get a good adhesion. 2. VERY EXPENSIVE! Bonding adhesive is not cheap.

Using the Dens Deck prime, you will need one application of adhesive on the cover board and one application on the membrane. Flop it on.

The cover board will also provide a smooth monolithic surface for adhesion. It really doesn't matter if you sand the OSB it's still not going to be as smooth as the cover board. And it's still going to be porous and still soak up the adhesive.

Additionally, I'm going to assume the osb was fastened most likely with nails from a nail gun. You will eventually get nails pops which WILL puncture the membrane.

The money you save on buying less adhesive will pay for the cover board.

Along with that, you will achieve a wind uplift rating of FM 1-90 and it would meet Carlisle's commercial warranty requirements.

If this was my project that's what I'd do. Just my humble opinion.

 

Must install 1/2" cellulose fiberboard to the plywood surface. Cellulose must be installed using plates and screws in a 2' square pattern, which is 15 per board, not 12 as some have suggested. Use a 60 mil EPDM fully adhered to the cellulose. Add 2x3 galvanized drip to the perimeter, fastened with wide head screws, and then install 6" edge tape to the perimeter to sandwich the drip between the EPDM and the edge tape. You could use ISO board instead of cellulose, but normally that is used to enhance drainage and eliminate standing water, or for insulation purposes. This is the manufacturer recommended method of installation, and the only method that will give you a worry free roof.

 

I never have liked adding the drip edge to rubber roofs. If there will be a gutter, it's pretty important, I just don't like the metal on the edge. I use term bar whenever possible.

In this case, I don't think he can have a gutter. At least not an effective one.

 

awesome

Really great design, these things are a look at the future.

 

Winter sucks.....

Thanks for the comments guys....yes...lots of 'bang for the buck'...
I'm at R46ish in the ceiling/roof...code here is R53. Soooooo....I either have to bump it up another R7 or sweet talk the inspector to let it 'slide' due to the design of the roof. Inside warm air doesn't really stay in one spot (relative to a flat or pitched ceiling)......it climbs to the highest points which are at opposite ends of the tiny home. So in theory...it keeps moving CW around the ceiling. I doubt he'll agree but....one can always ask!....lol. Another thing....this will be moved (sold) after completion so I'm doubtful any roofing will be applied until it reaches its destination, dependant of location of course. Not very good pics and excuse the mess but here ya go....

 

I already have the 10x100 ft 60 mil epdm, 100 ft of 6" splice tape, 200 ft of 6" edge tape, 2 large buckets of bonding adhesive, 6 tubes of lap cement, rollar, small container of epdm cleaner (if needed).....and a partridge....no pear tree....lol

Plan would be to apply a 1"x12" painted smart board, 1 termination bar....3/4" x 2.75"ish.... possible cement board(?). Want to pull the metal drip edge away from the facia. Metal facia could be installed at a later date if needed. If an 1.5" insulative polyisocyanurate (?) is used I would band the edge of roof with 1.5" x 2.75" (spilt a 2x6) lumber. Top of facia would be flush with the 2x.

Possibly....lol

 

Looks like the tarp managed to keep the roof dry.....:clap:....I was somewhat concerned over the course of winter...lol.
I've decided to install the epdm asap...weather permitting. Is there a temp that is the most conducive for the install? Here's a drawing of the layout of the epdm and fascia detail.....will start at the ends and finish in the center. Seems I can't find any termination bars locally, so....I figure I I could sandwich the epdm between the 2x10 and 1x12 fascia?... with the same results. The epdm should be wrapped over the edge to seal it up properly, do not want any air or water getting underneath when the tiny home is moved. Still not sure whether to use any cover board at all, seems to be mixed opinions on that. Would the washers/screws be visible after the epdm is laid? Assuming they would telegraph through?

 

Your detail looks like it could be a water trap with the EDPM being sandwiched between the fascias............

 

Yeah....have a Plan B in the works....lol
Will reduce the size of the 2x4 nailer and increase the width of the bottom metal facia to 5"ish. Just so the custom drip edge isn't isn't too flimsy on the vertical.

 

That looks better, if you can, consider putting a capillary break along the bottom of the 1x or run the metal fascia all the way up.

 

I figured i would cut the backside bottom out of the 1x4...half the width of a table saw blade. Maybe 1"ish deep (high)....so one could stuff the metal fascia in after the fact. It will be tight in the cut....but still float. Less of a chance of 'buckling' when the home is moved......not that it would buckle...lol.
Caulk if necessary.....

 

You are way overcomplicating this

 

Well...I'd probably cut the epdm flush with the edge of the fascia and simplify things.....but....since it's going to be moved down the highway at 50 mph+ I decided to seal the epdm a little better with some 'termination bars'.

 

Also...it enables me to get the epdm on the roof without any drip edge/ fascia detail. Get the roof sealed up and worry about the rest after the fact. Besides....it will look good when I'm done.....