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nota

cost of glue for 2600sq of plywood

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I need a cat 5 proof roof

I am in a neighborhood that andrew's eyewall passed thru in 92

the house did not come near flood or surge

and the basic structure was intact

but the roof was trashed and inside soaked

as I need a new roof AGAIN  do to normal leaks

so my plan is to screw and glue a 3 layer 5/8 plywood roof totaling 1 1/2+ waterproof base

the after the code required tar tarpaper and nails a peal-and-stick plastic layer

then a metal 5 vee roof with some peak lapping and  doubling and steel straps on the edges

 

so what is the cost of what glue the plywood makers use ? needs force ? needs heat ?

vs resorcinol glue need force? screws enough force  ? stack more weights ? 30k 66lbs at $300 looks do able

vs epoxy huge costs stinks toxic

vs titebond 3 type glues weak ? about $100 to 5 gal

per 2600 sq ft or per 100sf or per sheet of ply

or other glue ideas ?

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What about using a wood floor glue. With a v notch trowel then screw down into roof joists?  It's about $100 per 5gal. Buy/rent a proper screw gun or use a nail gun with ring nails.  Not saying it will 100% stay on in a cat 5 but it would be fucking strong. I'd want to make sure the hurricane tie down are properly installed too. 

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re-strapped after andrew inside to the concrete wall caps

I plan heavy steel over the edges 1/4 by 4'' u-channel strapped to the slab welded to a peak cap

the weight will be only over the CBS walls except at the peak an open inverted V shape maybe a 1/3 of a 8'' steel pipe

as one pipe 20ft would do the 44 ft peak  

belt and spenders approach is needed for a cat 5

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Other post on this topic:

I guess this is a derivative question, but I thought the context was useful.

If you're gonna do this, maybe also glass the joints? Any way to tie the roof directly to the foundation, not just the upper rim joist of the framed walls?

Your building inspector may have issue with anything out of the ordinary... as might any insurance claims adjuster you encounter in the future. That said, if you can overbuild it such that you can appease the inspector and AVOID failure that would require an adjuster, you might just win in the end.

Randii

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2 key things.

1 use screws to attach your roof to the joists not nails.

2 tie your roof joists to the foundation. In the Eastern Caribbean they use rebar running through the hollow concrete blocks and they are embedded in the foundation.

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20 hours ago, randii said:

Other post on this topic:

I guess this is a derivative question, but I thought the context was useful.

If you're gonna do this, maybe also glass the joints? Any way to tie the roof directly to the foundation, not just the upper rim joist of the framed walls?

Your building inspector may have issue with anything out of the ordinary... as might any insurance claims adjuster you encounter in the future. That said, if you can overbuild it such that you can appease the inspector and AVOID failure that would require an adjuster, you might just win in the end.

Randii

no frame [stick built] the walls are CBS on a concrete slab and topped by a concrete cap

hurricane straps are nailed from the cap to the trusses

I plan the 1/4 x 4'' steel down to under the slab welded in place over the roof edges after the top 5v metal and back down to the slab

 

I have no insurance as it is ONLY available from a STATE RUN CORP in my area

has too many high  deductions and only covers the structure [for the loan industry requirements]

so is not a good deal for the home owner and costs over 4k a year, 80k over 20 years with NO contents coverage just the shell of the house

far cheaper to do an over built roof I figure my costs at about 5k extra over a normal roof replacement

but I have had good luck to get new but over stocked plywood cheap from a condo builder who had to get the plywood off his completed job site

120 sheets brand new still strapped in the shipping bundles

and the steel roof from a change order [they went with the standing seam metal vs my 5v metal] so new but surplus to their job 

at a substantial discount [less then 1/2 retail ] so I am way under budgets so far

 

still need to pick and get the glue

at a big discount to get the 5v off their completed building site

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With all due respect, and I am a metal roof fan also, have you considered what happens to your dead loading? Triple layer of ply because of impacts? There is a tension between reducing overhangs for wind and fire safety and the loss of comfort and shade by reducing overhangs, generally closed soffits improve strength and reduce uplift. Pitch is also a factor. Increasing fascia strength is a cheap way to add strength, rafters also matter, particularly in the tails. Plate tiesare good, H7s are pretty strong, spreading out your nails matters. Industry standard is 4' load path. Best glue is going to be subfloor adhesive for this application, as noted.

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2 hours ago, Bruno said:

With all due respect, and I am a metal roof fan also, have you considered what happens to your dead loading? Triple layer of ply because of impacts? There is a tension between reducing overhangs for wind and fire safety and the loss of comfort and shade by reducing overhangs, generally closed soffits improve strength and reduce uplift. Pitch is also a factor. Increasing fascia strength is a cheap way to add strength, rafters also matter, particularly in the tails. Plate tiesare good, H7s are pretty strong, spreading out your nails matters. Industry standard is 4' load path. Best glue is going to be subfloor adhesive for this application, as noted.

shingles weight  is about 1 1/2 to 2  lbs per sf the metal weight is about a pound

total roof at 5 lbs per sf minus the shingles comes to 4 lbs per sf additional

or about the same total weight as a concrete tile or clay tile roof that uses the same trusses

so I do NOT fear the weight increase 1/4 metal straps will only be near the edges directly over the  CBS walls

only the top peak cap will be stressing the structure and if needed 4x4 braces can be placed under the top ridge in the attic

to transfer the weight load from the top truss wood to the bottom truss beams

 

btw the 120 sheets of 5/8 ply are now  on the roof in stacks 20 deep  no sagging or problems noted

I do not think the weight will be a problem

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Dead load usually has a factor of safety involved.  In Canada we use limit states design, dead load is multiplied by 1.25.  wind pressure by 1.4 and add a companion load.  5/8" ply wont cause a failure under normal circumstances unless you trusses are under built.  

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Nota I am curious. What protective coating do you intend to apply to the plywood and how long will it last

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Thompson's water seal and maybe a primer

it is under the tar paper and peal&stick vapor barrier 

I have no clue how long it will last

one cat 5 I hope !

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Thompson's water seal will not protect the edges. You need multiples coats of varnish or epoxy.

Thompsons will protect the outer layer but will need additional coats every 2 years. 

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Thompson's is also silicone-based, so if you use it, nothing else will stick anywhere near it.

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edges will be sealed with the glue or 5200 calk if a wider gap needs it

the plan is to get the edges to be a  close fit and glued to the next edge and try to avoid gaps

filling any voids with glue

we will see if I can do it that well

if not then 5200

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1 minute ago, Ishmael said:

Thompson's is also silicone-based, so if you use it, nothing else will stick anywhere near it.

oops will need to revise that use of Thompson's

I thought it soaked into the wood

so maybe just prime the top with thinned primer

I hope the glue will seal the under layers sides and fill voids by hand work

 

thanks!!,  the point of this post is to learn that kind of stuff

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anybody know the differences in wood floor glue

local home depo has

taylor 2071 Tuff-Lok X-Link Wood Flooring Adhesive 4-gal. with Meta-Tec Technology is a high solids, cross-linking, Amide-Ester-Acrylate, resin-based adhesive formulated for the interior installation of dry-back parquet, engineered wood at 79 for 4 gal

Henry 1171 is a high-solid, acrylic-urethane adhesive 100 a 4 gal

 Roberts R1509 is 100% solids moisture cure urethane adhesive glue formulated for the installation of solid, engineered and parquet wood flooring. 150 a 4 gal  

Roberts R1535 Premium 4-in-1 Wood Floor Adhesive is based on the latest innovative technology for Zero VOC wood floor adhesives. R1535 is a one-part, trowel-applied, 100% solids, moisture-cure urethane adhesive specifically designed for installation of bamboo, solid wood and engineered wood flooring.  at 169 for 4 gal

 

an other place has

Mapei Ultrabond ECO 995 Adhesive- 5 gallons

Ultrabond ECO 995 is a premium, 100%-solids, one-component, moisture-curing urethane adhesive for all types of wood flooring at 189 for 5 gal

 

what is good better best types ?

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Urethane glue offers some moisture protection. It protects hardwoods from moisture on concrete slabs.  Doubt it would work well under water, but you mentioned it just needs to survive one storm. I've used Bostik once. Seemed like a good product.  Mapie are quality floor adhesives for tilers, can't imagine they would produce crap. Other ones I have not seen.

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I think that you are over thinking this. Good that you have looked at the dead weight loads, 2 layers of 5/8" just seems a bit much, adding 1 makes more sense. Building it like a building rather than a boat makes more sense, using standard techniques like subfloor adhesive (big tubes), deck screws if nailing isn't good enough, looking at steepening the pitch to reduce lift if it's flat, protecting the edges with metal flashing maybe backed up with polyurethane caulk bedding where you think it wise, using architectual flat metal roofing screwed onto the sheeting, have a vented ridge cap, closing your soffits in, doubling up your fascia, these seem like common sense solutions in addition to having a proper strapped load path. The ridge strapping common now seems redundant, just don't see that many roofs that fail at the ridge but it doesn't cost much so why not. Using a self adhering underlayment sheet, adding isnsulation and ventilation, these are all standard commonsense approaches short of a building a pillbox or coldmolded boat. But each to his own. 

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just as 8 anchors on a sail boat allows 4 failures and an in place boat post storm

this house roof plan is to be OVER KILL to the MAX BUT SO ARE THE INCREASINGLY FREQUENT CAT 5'S

PITCH IS ABOUT 4 FT IN 16  NOT FLAT NOT STEEP 4 TO 1

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time to start buying the glue and filler for the plywood edge voids

so yet an other what product to fill the VOIDS IN THE PLY ???

IS THE FLOOR GLUE THAT i NEED IN BULK GOOD ENUFF  to fill voids ??

IS THERE A BETTER CHEAP PRODUCT TO FILL VOIDS

 

yes I know epoxy is the best but it is costly nasty smells ect 

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Epoxy is smelly? didn't know that.

Fill the voids? what voids, thought you were putting metal over it all?

Are you planning for what if all the metal blows off? If low profile screwed down metal blows off I'm not sure what you can expect from the plywood substrate.

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On 11/7/2018 at 6:44 PM, Bruno said:

Epoxy is smelly? didn't know that.

Fill the voids? what voids, thought you were putting metal over it all?

Are you planning for what if all the metal blows off? If low profile screwed down metal blows off I'm not sure what you can expect from the plywood substrate.

the small plywood edge voids in the non marine plywood I have

and if any sheets of ply have gaps to the next sheet try not but stuff happens

also may use on the 5v metal roofing esp on the multi layer parts and the overlaps

and just as a seam sealer on the plywood and metal

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Right, when I have wanted a more waterproof subfloor I have sealed all edges as the sheets are laid with the subfloor glue, just gets messy, use shoe covers, minimize walking, harder on a roof. Could do 1 course at a time, let set up.

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to change the weight calc

3 layers of steel 5v on the edges weight 3 lbs a sf but only near or over the cbs walls

1 or 2 layers alternately over most of the roof lapped at the peak so 2 lbs avg

2 added layers of plywood just under 2 lbs a sf so 4 total plus the 2 lbs of steel so 6 added

tap paper ect will be the same weight as before

I think I am in near spec for weight loads as a tile roof but tiles add little strength or load sharing ability

 

the only other new added load is the steel straps 1/4 by 4'' over the cbs walls on top of the tripled 5v steel

and the about 300 lbs split pipe on the peak welded in place to the steel straps so slightly selfsupporting by the straps wall sharing loads

I can add 4x4 supports if needed under the peak

 

still dithering on the glue choice or brand

 

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