How horrible are flat roofs?

[Guest]

I showed my older brother the listings of some houses I liked (mostly in Hollywood). He was quite dead-set against the house I like the best because it has a flat roof, being the main issue, with the other issue being that it appears to have air-conditioning retro-added recently in a manner that he said was prone to trouble. The house was originally built around 1977, and was updated recently. Old photos from google earth show that it was in a rather dilapidated condition a few years ago (though really looks great now). I asked our "family contractor" (he built my mother's house from scratch and totally re-did my brother's) what it would cost to put in a sloped roof, and he quoted some astronomic figure. There don't seem to be a lot of houses coming up in the neighborhood I'm most interested in. Do any of you have any experience with flat roofs? Are they really all that bad?

[MikeBiDude]

I showed my older brother the listings of some houses I liked (mostly in Hollywood). He was quite dead-set against the house I like the best because it has a flat roof, being the main issue, with the other issue being that it appears to have air-conditioning retro-added recently in a manner that he said was prone to trouble. The house was originally built around 1977, and was updated recently. Old photos from google earth show that it was in a rather dilapidated condition a few years ago (though really looks great now). I asked our "family contractor" (he built my mother's house from scratch and totally re-did my brother's) what it would cost to put in a sloped roof, and he quoted some astronomic figure. There don't seem to be a lot of houses coming up in the neighborhood I'm most interested in. Do any of you have any experience with flat roofs? Are they really all that bad?

They’re fairly common in CA from building from that era. Have a home inspector check, it probably isn’t “flat” but will have an slight slope to it.

[+ bashful]

In my younger, poor life, I lived in a one story apartment building in the Midwest with a flat roof. Occasional leaks, but some of my neighbors had constant leaks. I would think In southern CA, it wouldn’t be such a problem. I’d be more concerned that the renovations were a cheap lipstick job done in the height of the flipping craze rampant a few years ago, rather than addressing real problems.

Edited August 26, 2020 by bashful

[+ Kman]

I am not a homeowner nor a roofing expert but I have heard that flat roofs tend to "wear out" faster...my friend's parents bought a home with a flat roof (built in the 50's) and there was a lot of water damage and ceiling of that room was starting to come down. Don't know the other details about it. And this is in the upper midwest...more moisture and snow to contend with

[Epigonos]

As MikeBiDuke has said flat roof are quite common here in Southern California particularly in the dryer parts of the state. One sees a lot of them in Palm Springs for example. If your family contractor finds the rest of the house sound and in good condition I wouldn't worry too much about having a flat roof in Hollywood.

Edited August 26, 2020 by Epigonos

[+ bigjoey]

The problem with flat roofs is often the water does not run off and just “pools.” The slightest crack can then start to leak.

 

“Flat” is a misnomer as the roof should have a very slight slope to drain the water.

 

Does the roof have a parapet wall or does the water just flow off into a gutter on one side. The parapet walls and the joints can cause a problem.

 

Another factor is the type of “flat” roof. Is it covered in gravel? Is it “seamless?” Does it have seams? Does it have a warrantee?

 

Most flat roofs are good for about ten years. Sloped roofs should last longer.

[rvwnsd]

I had a flat roof on a townhome in San Diego and it developed a leak where water pooled. However, SoCal seems to be in permadrought and it is likely you would never experience enough rain to cause a problem. I'd simply get the roof checked every autumn.

...The house was originally built around 1977, and was updated recently. Old photos from google earth show that it was in a rather dilapidated condition a few years ago (though really looks great now)....

I would be more concerned about the extent of the rehab. If the place was truly gut rehabbed, complete with new wiring, plumbing, insulation, underfloor, and exterior cladding in addition to cool floors, fixtures, and walls then it will be fine. If it was a cosmetic reno, stay away. Not sure about Hollywood, but similar areas of San Diego were plagued with flips and condo conversions that looked amazing but preserved old infrastructure.

[+ BenjaminNicholas]

I initially read this title too quickly as 'flat roots.' That could have also been an interesting conversation.

 

As others have said already, just get a solid inspection. A 'flat' roof is no worry, not in that climate.

 

It's indicative of the time the house was built. Embrace it ?

[+ keroscenefire]

Agree with everyone that a flat roof would be fine in that climate. Flat roofs are really more of a problem not just in wet climates but cold ones since snow melts more slowly and has freeze and thaw cycles that can quickly cause cracks on flat roofs and sometimes heavy snows can even cause roof damage.

 

LA has such a variable climate...many years are very dry with less than 10 inches while other years are wetter with more than 20" of rain. Rainy years it would definitely be a good idea to check the roof from time to time to see if it is properly draining. You might need to clean out drains of debris and possibly add some roofing sealant to areas if they are looking like they are getting water damage. Roof sealants are fairly affordable and available at any hardware store. You should be able to do this work yourself as the sealant goes on similarly to paint with roller brushes and obviously getting onto a flat roof is probably easier than a pitched one. It would be a simple 2-hour (at most) project that would likely cost you only around $100 or so (depending on how big the roof is of course).

[+ azdr0710]

good points made above.....

 

as mentioned, check for ponding/pooling where the water is not draining toward whatever drain (scupper??) is set up to drain the roof......this will be very obvious (dried water marks, discoloration, flaking roof coating) .......

 

as said, flat roofs are not really flat because they do need to drain the water in some way......

 

periodic coating of the roof with a roof coating product is needed every four or five years (usually a white thick paint).....as said above, it's like painting with a long pole and roller brush.....easy, except that roof access is often the hardest part!......

 

some bemoan flat roofs, but regular maintenance is all that's needed......but check that ponding!!!

 

don't know anything about the AC concern without more detail.....

Edited August 26, 2020 by azdr0710

[Guest]

My first house had a flat room. It was a terrible experience. But that was in a rainy region.

 

Personally, I wouldn’t avoid it in new/modern construction with an eye toward detail...but in an older home, I’m convinced the maintenance costs would be higher.

[+ sync]

The current rapid and unpredictable climate changes may be another consideration.

[dbar123]

I just moved out of a condo with a flat rubber roof. It was fine but we had to have the roof "tuned up" every few years to prevent leaks. A guy would come by and look for small tears (usually from nails popping up) and he would patch them up much like a bicycle tire. He would also check the seams to make sure they were good. It was fine...no more of a hassle than shingles as long as you are scrupulous on maintaining it.

[mike carey]

I've never seen reports here about there being problems with flat (actually slightly sloping) roofs. From the discussion so far, it's not clear what normal roofing materials in the US are, and that would make a difference. Here, they are invariably sheet metal, usually corrugated galvanised iron or some other sort of moulded metal sheeting, with a metal gutter on the lower side leading to a metal downpipe to take the water away. (Sloped roofs would commonly be concrete or terra cotta tiles.) Roofing metal is durable and you would expect it to last for 40 or more years. The house my mother built in 1968 (with a sloping roof) is showing signs of rust now so I'll probably need to replace the roofing iron shortly.

[Rudynate]

Thousands of houses in San Francisco have flat rooves. Nobody seems to have any problem with them. We've owned our house for 15 years and not had any trouble with it. Many San Francisco houses have light wells. About five years ago, we had to replace the roof in the light well at a cost of $2k. I had the roofer look at the roof on top of the house and he recommended some minor repairs, which we had done. No real problem before and no problem since.

[Monarchy79]

Another possible solution to flat roofs are to make them “green roofs”

 

https://www.sempergreen.com/en/solutions/green-roofs/green-roof-benefits

[Guest NYCRich212]

My experience says avoid, but my dealings with flat roofs have been on the East Coast.

Also, the late ‘70’s was not a great time for quality construction. It would be imperative, like said prior, to get the extent of the reconstruction.

 

If a permit was issued for the new work, and most certainly was, there will be file of the extent of work and if the inspector had concerns following the completion. In my world, it’s the Code Enforcement office you get this information.

 

Another thought, if there was leaking, and you should assume yes based on the condition prior to the rebuild, I would be as thorough as possible looking for signs of wood rot and insect damage. Damaging insects thrive with any leakage. Obviously, if the home is block or concrete these concern may be minor.

 

When it comes to roofs, one sign of a lousy job would be poorly installed flashing. And, Also to understand the way the system was designed to move water away from the structure is important. Both evident to the eye.

 

Also, if it was a membrane roof, you should be able to chase down the manufacture and specific product, and that will allow you to access longevity. But, as mentioned before, roofing quality always depends on installation.

 

I’m sorry to have probably repeated the obvious, but your older brother would probably do well in the long run to have peace of mind with his home construction even if that means venturing outside his preferred neighborhood. Good luck, as you know, new property goes on the market every day!

[+ FreshFluff]

As MikeBiDuke has said flat roof are quite common here in Southern California particularly in the dryer parts of the state. One sees a lot of them in Palm Springs for example. If your family contractor finds the rest of the house sound and in good condition I wouldn't worry too much about having a flat roof in Hollywood.

 

Eichlers have them, too.

[+ Charlie]

Our last two houses had flat roofs. The one in Philadelphia was a three story town house, and we hated it: there is nothing like climbing up onto the roof in the middle of the night during a blizzard to try to shovel snow off it, so that the bottom layer doesn't turn to ice from the heat of the house below, and later melt and find its way into the house. OTOH, the one in Palm Springs, a mid-century modern one story, was no problem at all, even on the rare occasions when it rained.

[MikeBiDude]

Eichlers have them, too.

Yes mid-century influence ??

[+ RJD]

Our last two houses had flat roofs. The one in Philadelphia was a three story town house, and we hated it: there is nothing like climbing up onto the roof in the middle of the night during a blizzard to try to shovel snow off it, so that the bottom layer doesn't turn to ice from the heat of the house below, and later melt and find its way into the house. OTOH, the one in Palm Springs, a mid-century modern one story, was no problem at all, even on the rare occasions when it rained.

 

Did we own the same house? ?

 

Same here. I had a two-story in Philly. We had snow and the temps were ridiculously frigid for an extended period so nothing melted except the bottom layer from the heat of the house. The water didn’t have anywhere to go and made its way inside. To make matters worse, the seams of my rubber roof weren’t sealed properly. The drywall ceiling in my guest bedroom was so saturated it was leaking in several places, including the ceiling fan, and sagging so badly I had to puncture holes in it so the water could drain and didn’t collapse. I had to get my roof replaced, the joists needed to be treated to eliminate mold, new ceiling and one wall damaged.

 

They do sell a heating element that can be installed in your gutter and downspout. When you get snow and consistently cold temps you plug it in and it keeps the gutter and downspout clear of snow and ice. The bottom layer melts, but the water isn’t backed up due to ice in the gutter and downspout.

[+ Charlie]

Did we own the same house? ?

 

Same here. I had a two-story in Philly. We had snow and the temps were ridiculously frigid for an extended period so nothing melted except the bottom layer from the heat of the house. The water didn’t have anywhere to go and made its way inside. To make matters worse, the seams of my rubber roof weren’t sealed properly. The drywall ceiling in my guest bedroom was so saturated it was leaking in several places, including the ceiling fan, and sagging so badly I had to puncture holes in it so the water could drain and didn’t collapse. I had to get my roof replaced, the joists needed to be treated to eliminate mold, new ceiling and one wall damaged.

 

They do sell a heating element that can be installed in your gutter and downspout. When you get snow and consistently cold temps you plug it in and it keeps the gutter and downspout clear of snow and ice. The bottom layer melts, but the water isn’t backed up due to ice in the gutter and downspout.

All three of our houses in Center City had flat roofs. All of them had water problems, regardless of whether they were built in the 1980s or the 1880s.

[Deadlift1]

Ifyou don't get much precipitation you shouldn't have a problem. I'm sure there are plenty of other homes in the neighborhood with flat roofs. There are most likely one or two local experts that service those homes. Flat roofs need to be inspected every couple of years.