Corrugated Roof Is Leaking.

CNC

Ok so i have some problems at my shop, we take care of our landlord and do the maintenance on our building, and a huge commercial building, its pretty old, and we have a section of the building that was added to it with corrugated roof, its pretty old also, im saying , at least 50 years old. wood framing.


its about 8200 sq ft of corrugated steel roof, nailed, only pitched one direction around 25-30 degrees. we are having issues with leaks, through some seams, and pinholes from nails that have come out, and alot of nails are loose from over the years.

You can see that come people have driven roofing screws next to the screws and sucked it back down, but then the nail is sticking out around a half inch, then they push those down and use a tiny bit of roof patch. Is this ok? will it work? We have considered re screwing the whole roof, just like the nails, but next to then to re secure the panels, then roof patch any holes, and push the old nails back in place, but the screws will hold it. The roof is in good condition, just the nails backing out are causing leaks. we calculated rough 10,000 screws. what do you guys use to drive them, just impact drivers? cordless? ITS ALOT OF SCREWS!


advice?

Ed the Roofer

A screw gun made for decking screws. Any fastenal or such supply should carry them. You do not want the high RPM drywall screw guns though.

A DeWalt cordless works good too, with a variable speed and clutch with a setting so you do not overdrive them.

Don't use plastic roof cement mastic, though. I think Vulkem, or one of the other higher quality exterior caulks would be best. Then, if you really want to, you can elastomeric coat the entore roof after the screws are all down and sealed.

Ed

neolitic

We had the same deal on a
(much smaller)storage building
that we used to rent.
I used Vulkem under the seams
after pulling the nails holding them.
Then we just pulled all the nails
and ran pole barn screws
(the ones with the neoprene washers)
through the same hole the nail came
out of instead of making a new hole
and sealing the old one too.

Not what I'd call fun, but our stuff
stayed dry, and the rent check stayed
in our pockets.

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CNC

elastomeric coat, whats this?

I have though that it would be a good idea to pull the nails, vs leaving them, but thats a HUGE project in its own, and figured leaving them if possible would shave a god week off the project! its HUGE

neolitic

Never said it was fun
Up side is since they are breathing out
they pull easy, screws don't have
to cut their own holes (quicker),
you don't have to seal all the nails,
and the old nails will pop up
again!

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Slyfox

You could break the job down into portions.

I have a maintanence contract on 8 buildings and all have metal roofs and we started the contract in fall of 2003,
we stopped the leaks that were ocurring at the time and than scheduled to visits a yr, once in spring and once in fall, this spring all we have to do is a walk over inspection because every building has been resecured and leak free since we started, meaning every fastener and penetration has been recealed and is just a matter of checking on them acouple times a year now and keeping the roof cleared of mother natures debrees.

Doing it all at once is a big job, doing it in pieces is acouple days work acouple times a year.

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rbsremodeling

Elastomeric paint is paint frequently use to paint roof surfaces. I have used it on metal and directly on wood sheathing as a roof coating. If I remember correctly we use to do 2-3 coats that where on avearage 3 mil thick. I normal comes in white but I have seen it in several colors as well. It can be tinted.. Think of it like the silver paint used on rubber roofs

We use cordless impact guns on the screws. We use srews with the rubbers seals, But that is a big roof and a lot of screws

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CNC

Thanks for all the good help, i think the conclusion is, we will rescrew the whole roof, next to the old nails, then go back, and pull the bad nails, and caulk the holes? and any nails that are sealed really good, we will keep them in place.

Im going to try and keep pushing to paint the whole roof, what manufacturer do you suggest for paint? (elastomeric) I need quite a bit, so 5 gallons at a time would save cost. i assume its not sprayable, ill have to roll it? THanks again guys!

rc-construction

There are hundereds of companies that manufacture acryllic roof coatings right now. I do not sugguest just coating the roof though. Metal Roof Restoration is 80% of my business. ALL of the fateners need to be coated liberally with a flashing grade material, ALL seams both vertical and horizontal need flashing grade and some sort of mesh. Just coating a metal roof will not do much for you because of the movement of the roof. Seams and fasteners have to be treated first. each manufacturer will have their own flashing grade and mesh to sell you. You can roll any of the acryllics on with a roller but it takes FOREVER. If you choose to spray it your cheapest route is a Graco GMax 7900. Nothing smaller than that will spray it worth a damn. It's too thick. You should figure 3.5-4 gallons per square on material depending on whose material you use. Remember there will always be a base coat and top coat, same goes for the seams. I do not recommend rolling it.

Here are just a few manufacturers we are certified through. You'll find them on the internet.

TOPCOAT by GAF
Conklin
Roof Mate by United Coatings
Raintek

BTW it is not paint.

neolitic

If you pull the nail and run
the screw into the nail hole
you don't have to fill anything.

All the nails are either loose,
or about to be loose.

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Red Adobe

3 guys could rescrew it pretty fast/ 1 pulling nails the next screwing, and the 3rd cleaning up and handing beers.

Elastic coats are labor intensive and still have to have a solid substrate, you also MUST tape seams. On a 50 yr old roof its a bandaid at most and at $60-100 sq material cost Id be looking at R-panel as a replacment if possible

CNC

When referred to it as $60-100 per sq. material, what... a square foot??? or is that a trade term, that refers to a certain increment?? (sorry that might be a stupid question.

OK so far the roof has been rescrewed completely, not ALL the nails got pulled, but anything that was bad was, and the entire thing was screwed. WE HAVE to get this coated before winter.

Im going to call around for flashing grade sealer and mesh, and get prices for elastomeric paint, but need a figure to base it off of, 3 coats? I will see about renting a sprayer, would we then back roll it, or just spray it? A good pressure washing for prep ok? Thanks for the input.

MALCO.New.York

If you are pulling nails and setting screws back in to the same hole, I would suggest filling the hole with caulk then driving the screw. Works "like a charm".





http://www.mbtaus.com.au/acrobat/6134.pdf

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roof-lover

Malco used the word "suggest"

He was being nice.

His experiance speaks... I think what he really means though, is that it is the only way to do it.

When you pull the nail, it enlarges the hole. and when you screw through the hole (even though there is a neoprene washer)
It isn't good enough.

Squirt polyurethane into the hole, then screw it.
NP1 is perfect for that.

MALCO.New.York

Much is Grassy Ass!!!

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LA_nailer

[quote=CNC;511475]When referred to it as $60-100 per sq. material, what... a square foot??? or is that a trade term, that refers to a certain increment?? (sorry that might be a stupid question.quote]



The term "per sq." means 100 square feet.

CNC

the new screws were screwed next to the nails, and old nails were pulled and patched, we have determined this coating will be a band-aid....Hmm... i wonder how much the coating will cost in material. Trust me i want the roof replaced too. i dont think thats in the cards this year. I lost my ass on my google stock. kidding!

rc-construction

I can show you where to get the material cheap and get training to do it yourself.

white_roofs@yahoo.com