Hello All,
I have a flat roof which collects a tremendous of water after it rains. Does anyone have any ideas on how to fix it. Is it possible to convert a flat roof to an inclined one? Is it costly? Any ideas and suggestions would be greatly appreciated.
-Murali
Aflat room should be pitched slightly so that water will run off one end. If the support joists have sagged that may be preventing adequate runoff.
It is certainly possible in many cases to replace the roof, such as on older mobile homes but the cost is fairly high
I would try to get someone to inspect the roof and give you a report on repairing or replacing it.
It just occured to me that there were some flat roofs which were effectively a tank that drained through one or more large downpipes. If thats the case check for any blockage of the drains
Our condo assn. got estimates for correcting such a problem. The bid mentioned something called "Firestone APP-Cool" - described it as a tapered foam composite that adds slope to a flat roof and insulates it. Has to be covered, and I am not familiar with the process so went looking at Firestone's website for info. I don't find a product by the name we were given, but here is a link for something similar:
Why people design buildings with flat roofs is beyond me. It isn't rocket science to know that flat + water = leaks. Cost of construction I suppose couild be a reason but then when you factor in the cost of the high tech covering (that will leak) plus repair thereof several times where is the savings? We recently spent a couple million to covert the HS flat roof to a peak roof to correct the problem. Also spent over a million re-doing the flat roof on the court house and jail. Interesting that the jail roof still leaks in the same spots.
I haven't bought many houses in my 70 years but when I was shopping I wouldn't look at anything that had a flat roof on any portion thereof.
Harry K
Certainly it can be done. The cost depends largely on if you take off the old roof, or just build up a new one. When I moved into my home many years ago, the living room (which was originally a wide porch) had a shallow pitch which leaked many times over the years. It was a shed roof addition onto the hip roofed main portion of the house. The room had the pitch raised two times by previous owners!
I found that the very first roof was nearly flat, a hot tar roof with just enough pitch to drain. Sometime long ago another roof was built over it using
2x4 sleepers, with the high end raised a bit more. Finally, someone added a third, similar roof structure, pitched a bit higher yet. But even this last roof was less than a 2/12 pitch. The closed in areas between the various roofs were dry rotted from lack of ventilation and small leaks. Some of the rafters were so black and crumbled from rot they looked like they had been through a fire.I ended up tearing the entire roof structure off the whole house, not just the living room addition and building a proper 5/12 pitch gable roof. Here is a link to the before and (almost) after. I am also adding a two story addition to the rear.
-- Dennis
Anecdotal evidence from the apartment where I used to live:
After my complaining for three years about the leaks in the kitchen ceiling, right on the two ceiling lamps, the owner gave up on going up to the roof and trying to patch anywhere he thought might be the cause and called the roofers. Some days after the new roof was in place we had some snow and as soon as it warmed up water rushed down in the wall space between the kitchen and the bathroom. Luckily for me this time it went straight to the two apartments below, who were flooded, and I only got to see it through a hole under the kitchen sink.
In short: Neither the owners, nor the roofers had thought on looking at the rather old vent pipes, and one of the pipes was rusted through which had been the cause of the leaks. All they would have needed to do was break the wall of my bathroom and replace the pipe, instead of paying 8.000 dollars can. for the roof. It was solved by 'temporarily' plugging the vent -it was never repaired, now the building is being turned into luxury condominiums with the help of some paint.
Geo
The roof does leak above the kitchen. There is a one big pool of water above that location. I have no idea on how to trace the leak with out tearing the whole ceiling above the kitchen.
-Murali
PS: Thanks everyone for the great info.
Definitely possible - I've seen this done on everything from single family homes to condo complexes.
The conversion needs to be done by a contractor who understands the issues involved - for example on a flat roofed structure the roof and supporting walls are designed to withstand a mostly vertical load, once a pitched roof is added there will likely be additional lateral (outwards) loads present, so the modifications need to be designed and everything tied together to withstand the new loads.
You will also need to consider how to modify roof penetrations such as chimneys and vent - strange things happen if you don' think it all through :
Another issue is height - in my area many newer flat-roofed structures were designed to *just* comply with zoning requirements, in such cases if you want to add additional height a variance may be required.
So the place to start is the local building department, to see what would be involved in permitting such a conversion.
Michael Thomas Paragon Home Inspection, LLC Chicago, IL mdtATparagoninspectsDOTcom
847-475-5668
One thing i've seen is using spray foam and some coating (perhaps rubber sheeting) to regrade the roof to drain to some corner where the water is drained. You also get the benefit of lots of insulation--- (R6-8 per inch) on your roof.
Can't give you a link off hand... but i'm sure google can help there.
good luck!
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