Flat warehouse roof depression leaking

I have a warehouse with a flat roof. It has two drains and is supposed to be inclined uniformly towards the drains. However, between the two
drains, a depressed area appeared and water pools there. From there, it leaks down into the warehouse.
I am looking for cheap workarounds to stave off roof replacement. I am wondering how hard is it to add a roof drain and connect it to existing drains. Will that help?
i who hates flat roofs
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Depending how long it's been leaking, could be very hard, as you might open it up to add the drain and find that the thing is rotten from years of leakage.
You could look into having someone build up the low spot with spray foam roofing (or resurface the whole roof including building up the low spot, depending how much $ you are blowing on heat out the roof.) If the underside of the deck seems solid in the area, that might work well enough for long enough. If it's clearly rotten all the way down, you likely need to give up and have a real repair made before it gets worse.
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On Saturday, September 28, 2013 9:29:34 PM UTC-4, Ignoramus795 wrote:

How deep is the pool?
Where I used to work, they had additional roofing added to the original roof. The amount of material added caused the supporting beams to sag. But there were no problems until it snowed and then rained over the Christmas holiday. A large part of the roof collapsed. They ended up tearing down the entire 100,000 square feet warehouse.
Dan
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A depressed area usually means structural damage . Fix it right , and fix it now . The longer you wait the more damage will occur - and standing water will accelerate the damage . Doesn't necessarily mean a complete replacement , it is possible to repair the damaged area only . -- Snag
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On 9/28/2013 9:29 PM, Ignoramus795 wrote:

You can try to jack and sister the beams and boards first and take a golf ball up on the roof and roll it around, put a drain in where it stops rolling.
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On 9/28/2013 9:29 PM, Ignoramus795 wrote:

Minor ponding is normal for flat roofs, just call a roofer to fix as the leaks can be difficult to locate unless you have experience.
If you own a building, you need a good roofer in your rolodex!
MikeB
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On 9/28/2013 8:29 PM, Ignoramus795 wrote:

Every flat roof has low spots eventually...
Cheap fix is probably the more expensive in the longer run.
Part of the cost of doing business is the facility; spend the money and get it done correctly is my advice.
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And what would be the correct way?
i
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On Sunday, September 29, 2013 10:38:33 AM UTC-4, Ignoramus11700 wrote:

Kind of hard to say without a lot more details. How deep is the pooling? How big a surfare is the pool. What is the decking under the roof and what is supporting the decking.
You might be able to jack up the roof decking and then put on some sealant like they use on house trailers. But not a good idea for a very deep depression.
Or you might build up the depression using foam insulation and then cover that with EPDM Rubber Membrane.
Too many unknows.
Dan
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wrote:

Call a roofing company, you cheapskate.
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Around here they slop hot tar onto a couple layers of tarpaper with a mop and then top it off with a layer of course white rock chips, marble probably.
If you don't use chips, the tar will crack similar to mud in a dry lake bed.
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The temp ranges here in Chicago are pretty extreme and any leaks get big really fast. Looking up to see where the water is leaking followed by a trip to the roof is going to answer where your leaks are.
One problem with old buildings here is the amount of junk up on the roof. You can barely even walk around on some commerical buildings because of all the footings from removed HVAC units, signs, and all the plumbing and electrical junk related to that stuff.
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On 9/28/2013 8:29 PM, Ignoramus795 wrote:

You don't mention how your roof is made. We are all just guessing. I suspect a flat deck made of exposed steel bar joists with metal deck and 3 or 5 ply roof on pearl board with gravel ballast.
A re-roof to current code will demand a minimum of 1/4 in 12 pitch. This is usually accomplished with shaped Styrofoam. The popular membranes now are Modified Bitumen or TPO.
Adding a roof drain is fairly easy, especially if you can travel in the bar joists to an outside wall. I would think it would be hard to make grade joining to another existing drain. The added roof drain does NOT fix the roof, but it does get the weight off.
As someone else already noted, you should certainly have a roofer that you trust and knows your roof.
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What about "Foam roofing"? Where they spray foam on top of everything? Is that a scam?
As for TPO vs bitumen, which one would you recommend for Illinois? I am coming to a conclusion that I need to just redo the roof, instead of half measures, and live happily thereafter.
i
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On Sun, 06 Oct 2013 15:59:56 -0500, Ignoramus18857
BIG SNIP

Hey Iggy,
The foam is for insulation ONLY. It W I L L float off if it isn't under the sealing material, or buried in stone.
And I recall going to a fairly new apartment building with new flat roof where they had laid that 3" thick X 24 " X 48" fairly hard blue insulation on top of the sealing stuff (sheet rubber???), and then laid patio stones on top. The whole roof was floating around and the wind had it crashing into stack vents and such. It was scaring the tenants, and the building manager was scared of going up on the roof, so he decided it must be one of the elevators and called me.
Take care. Good luck.
Brian Lawson.
ps...I think your first idea about adding a drain is a good idea.
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Ignoramus18857 wrote:

I think you need to have the roof inspected by a reputable roofing company if one exists. Just because you have a leak in one location does not necessarily mean that the rest of the roof is at the end of its life span, though it could be. Think of it like a vehicle, you might have a bad rust spot where a rock chipped the paint - this doesn't mean you need to replace the entire body of the vehicle. Similarly your roof might have one spot that had a flaw when it was built, or it could have been damaged when someone was working up there on A/C or something.
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Raising the low spot (supports, shims etc from the underside/interior) would prevent the water and snow melt from pooling. Water freezing repeatedly in a leak path is only gonna make it worse.
Slap some sealer or membrane on the affected area and luck is your uncle.
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Also, any idea how I can find roofers I can trust? I called a bunch, and only one actually showed up, believe it or not.
i
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On Sun, 06 Oct 2013 16:01:08 -0500, Ignoramus18857

Go find a building similar to the one you want to re roof that is in the process of being re roofed. Get the name of the roofer from the sign on the roofers truck. Wait 90 days after the roof is complete then ask the people in the building about the quality of the roof and the contractor. It took me two years to find a roofer when I needed to repair my home.
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Try this guy Celso Garcia. I hope he's still in business. 20 years ago he stripped 4" of old asphalt off my flat roof and laid down a rubber modified bitumen melt down roof that has not given me a lick of trouble since. He was also the lowest bidder.
Pay for the silver coat. GARCIA ROOFING INC 4860 W NEWPORT Chicago, IL 60641 (773) 851-5244
Paul K. Dickman
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