Bentonite

[Anonymous-0]

Hello folks. I've got a very serious problem. There is a leak in the roof submerged under standing water. The roof is just about the worst design you can imagine, a V shape the entire length of the house, with the low point in the centre, sort of like a normal peaked roof turned upside down. The guy who built it probably grew up in the desert or something, because he sure didn't figure on a Canadian winter when he built it (Italian fellow I believe). Over the decades, the weight of snow and water has left depressions in the roof surface, which leads to a lot of standing water, the whole length of the roof in the middle is submerged actually, with the puddle being about a yard wide, and about 2-3 inches deep. I've been fighting with this roof for 6 years now. I mostly had it solved up until about 3 weeks ago, when it suddenly began dripping, not just in one spot, but along the entire length of the hall. I plastered some emergency roof repair into the low spot where I suspected the leak was, but it didn't solve anything. I was up again today, and found a sucking air bubble that squirted water and air when I stood on it. I tore it open and slathered patching compound up underneath it, then replaced the roofing mat, but nothing works. I'm at my wits end. It's my friend's house. She rents rooms for her income, and she obviously can't rent in this situation. It's bottom of the ninth and two out as far as money is concerned. If we can't come up with some sort of fix, no matter how temporary, everything is lost. It's been a very sad and stressful Christmas. I've been reading about sodium bentonite as a sealant. I was wondering if anyone knew anything about using it as a roofing repair, how much it costs, and where it could be had. I'd pour it into the standing water and hope for the best if I could. I know it's a very long shot, but straws is all we've got to grasp at right about now.

 

[Anonymous-0]

read Wikipedia, a couple of types.

 

[2x4]

a rubber roof properly installed will delay the problem for about 15 years. Maybe a pond liner to cover it also.

 

[S.Crum]

Bentonite works pretty slick for fast, TEMPORARY,emergency repairs on flat roofs at work. I'm sorry to say even in tight money there's no good way to cobble a poorly designed roof. Best case scenario would be to redesign the construction of the roof to drain properly and with the strength to withstand the local weather.

 

[Anonymous-0]

Rebuild the roof framing to make it right.

 

[Anonymous-0]

Rubber = EPDM, I assume. Maybe you could line the trough with a strip just wide enough to catch & channel most of it? Other than that, I agree with others that it is rebuild time. Too often, what looks pretty on paper or built is a b_ _ _ to maintain.

 

[T_Bone]

Hi Roger,

I think Benoite will NOT seal because it will expand/contract at a different rate than the existing roofing thus always be cracking for a new leak. 2nd, Benoite will be heavy and will probably cause more problems than the original.

I would use some OSB to form a bubble crown in the problem area at 3 times the height of the problem while using the bubble tie in edge to direct the water to run off instead of ponding.

A mental pic would be a chord of a football section.

The bubble build up framing can be made on the ground then lifted into place in over lapping sections. Once the temporary framing is in place then it can be sealed to the existing roofing.

Use a plastic broom to sweep away the water before installing the temporary framing. You can also dry the area with a LP weed burner if your careful and take your time.

I would use a 30# roofing felt as a slip sheet on the new framing. The slip sheet is to separate dissimilar materials so they can move without breaking the new seal.

Install 90# rolled roofing as a final cover over the slip sheeting then use multi-over lapping layers with roof mastic to form a seal from the existing roofing to the new temporary roofing.

About $300 in materials ???

Anything less and I think your wasting your time.

T_Bone

 

[Tim B from MA]

Cheap temporary fix?

One or more drain lines in the hall / notch of the V, and out through the wall.

 

[jim in N M]

Roger, Bentonite will fix it temperarally? ,it seek the leak and plug it for a short while. The school system here fixes them useing just plain Portland cement, BUT than it has to be torn off completely and re-roofed ....Jim in N M

 

[Anonymous-0]

I have been fooling around with bentonite for several years trying to seal a dam and pond. It comes in many forms from as fine as cement to chunks bigger than dog food. It also is used as a sealer after being broadcast on ponds and settling to the bottom.

I think the very fine stuff might settle down for an emergency seal. Bentonite has a very high coefficient of expansion when hydrated (I think like 30 to 1 or so) but stays in place when it dries out. It also wouldn't add much weight since a thin layer would do it. Its worth a try in the middle of winter and is cheap. You can get it at a well drilling supply store among other places.

Also, it is a real mess to clean up. BTDT when my wife thought it was pea gravel and used it as decorative fill around bricks in the ground. Pretty exciting to see gray ooze coming up between the bricks for no apparent reason during a rain.

T-Bone and the rest are of course right that it has to be rengineered and rebuilt to solve the problem and the bentonite should be thought of as an emergency fix only.

Good luck, I hope you can help your friend out.

 

[Anonymous-0]

I repaired a flat roof with a rubber roof.We have a lumber yard that carries ruber roofing. you just tell them what size you need and they cut to size. one big peice of roofing you glue down my size was 20'wide and 56' long. that was 2 years ago. It has never leaked. It was around 500.00 with the glue. DS

 

[pat sublett]

I have had good luck with a product called Snow Roof. It contains a patent chemical called ELASTOMERIC. To do it right you have to put down a primer and embed rayon webbing in it then 2 or 3 top coats. Sherwin Williams owns the product. I used to own an Ace Hardware store and sold it. I had a flat roof with a low spot about 6' in diameter and about 4" deep. Water stood on it all time and I fixed it with Snow Roof.

 

[2x4]

correct

 

[T_Bone]

Hi Roger,

Plan "B", Dry the area with a plastic broom then buy 5gal of roof mastic, the fiber type is better, about $60, a flat top sheet off a bed, using a elbow long rubber glove, spread goo on the surface then lay down the top sheet then apply more goo, continue until done while over covering the problem area very well.

The sheet keeps the roofing mastic from cracking out upon the expansion joints.

This would last 3 too 4 yrs.

Be careful of the dip area as I suspect the plywood will be rotted out and it'll be easy too fall through.

T_Bone

 

[T_Bone]

Roger, send me a e-mail. I just re-read your thread and would be willing to help you out.

T_Bone***Happy New Year***

 

[Anonymous-0]

That sounds like a good fix for this roof, one big sheet of rubber. As it stands, the leak has stopped with the dropping temperatures, but that is hardly reassuring. General concensus here is to sell the house for the lot value and move on. We are carrying out some temporary emergency repairs to get us through to the spring (not pretty, but it should work). Thanks to everyone for the suggestions. Happy New Year to all!

 

[T_Bone]

Hey Roger,

I don't think rubber roofs can be installed in the winter as the glue will not set up because of the cold temperatures.

I know you have to heat the patch's up if under 50ºf ???... CRS but somewhere in that range

T_Bone

 

[Texas Sand]

Around here people often put a metal roof over the original roof on older or poorly built buildings. Not cheap as you want but very long term. There are a lot of older flat roof buildings and when adding the metal roof they will build a peaked frame for the sheet metal. Also could gain some storage under the new roof.