Author Topic: why *wouldn't* you have a roof overhang?  (Read 1241 times)

nereo

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why *wouldn't* you have a roof overhang?
« on: July 18, 2018, 07:18:16 AM »
Recently had to redo some siding due to water intrusion from a poorly installed gutter, and as a result I've been noticing people's roof lines a lot more.

Lately I've noticed quite a few homes (generally colonial style) where there is zero overhang on at least two sides of the house (generally the pitch side, but not always).  I'm not a roofer but this just seems like a really poor design - any light breeze or debris on the roof and the water trickles down the side of the building.  Is this a dumb design, made to save a few $ on materials but leave the home more vulnerable to water intrusion, or is there really no advantage to having a 6" or 12" overhang all the way around

FWIW these aren't very expensive nor very cheap homes, but your run-of-the-mill lower middle class dwellings.

zolotiyeruki

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Re: why *wouldn't* you have a roof overhang?
« Reply #1 on: July 18, 2018, 08:16:26 AM »
For the builders, margin is everything.  On a $250k house, a few hundred dollars saved on labor and materials for that overhang can make a noticeable impact on the bottom line.  It's not just the overhangs, but a hundred other similarly small things that each save dozens-to-hundreds of dollars.  Like moulding or fascia made from MDF instead of solid wood, 2" toilets instead of 3", tile that only goes 18" above the tub (if there's no shower there), rooms with switched outlets instead of a ceiling box for a light fixture, the bare minimum attic insulation, etc.

It's a matter of economics.  The vast majority of buyers are sensitive to price and appearance (easy to see), not to quality of materials or workmanship (harder to notice).  A builder that spends the extra money to build a high-quality home will have a much harder time staying in business.

Jon Bon

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Re: why *wouldn't* you have a roof overhang?
« Reply #2 on: July 18, 2018, 08:24:37 AM »
Yeah I hear you on this.  On of those little things that cost a few hundred bucks extra while the house was being built but makes all the difference NOT having it.

Its the old adage you could make the house 50% stronger for 5% more cost, but no one does this, because cost.

All houses should have an overhang!


Car Jack

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Re: why *wouldn't* you have a roof overhang?
« Reply #3 on: July 18, 2018, 08:48:09 AM »
Overhang is awesome.  On my own house, the south side is lots of floor to ceiling glass with a 2 foot overhang.  Blocks the summer sun but winter sun gets in (sun is lower in the sky in the northern hemisphere in the winter).  No water issues, the glass never even has droplets.

For some reason, the north side of the house is traditional cape looking with about 1/2 inch of overhang.  We've tried gutters (they have all sucked and all been removed, usually because they fail in the middle of a huge rainstorm and cave in, pouring all the water directly on a window).  I've certainly thought about having the roof extended about a foot to end the dripping onto the side of the house.

Radagast

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Re: why *wouldn't* you have a roof overhang?
« Reply #4 on: July 18, 2018, 09:09:32 AM »
Less wind uplift :) but that is proportional to overhang length, so if you only have a small overhang that seems purely beneficial. Or, if you live in a stone house with a fire resistant stone roof, like a castle, maybe.

nereo

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Re: why *wouldn't* you have a roof overhang?
« Reply #5 on: July 18, 2018, 11:14:27 AM »
Thanks for the replies.  Seems this is yet another example of being penny-wise and pound-foolish.  I like the adage @Jon Bon said regarding a 5% increase in cost resulting in a 50% stronger house, but no one wants to - because cost. 

We have a long-term plan to build our own home in 3-5 years, and I'm keeping a mental list of all the shortcuts builders make to improve their bottom line (thanks @zolotiyeruki). I've lived in enough homes with insufficient insulation, poor acoustic dampening and improper drainage - all of which could have been solved with a rather paltry sum at the time of construction.

freeat57

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Re: why *wouldn't* you have a roof overhang?
« Reply #6 on: July 18, 2018, 04:16:38 PM »
In many cases, I'd go with the folks suggesting that the builder was just skimping.  In some cases, the houses may be styled to look a little like the cottages you see in climates where the potential for ice dams is high.  (Look at Scandinavian houses.)  When there is a lot of wintry precipitation with temps slightly above freezing during the day and well below at night, ice dams can form on overhangs and cause melt water to back up the roof and under tiles or shingles causing leaks. 

sokoloff

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Re: why *wouldn't* you have a roof overhang?
« Reply #7 on: July 18, 2018, 06:24:31 PM »
There should be a drip edge on any roof edge, to force the water to break free of the building and not run back towards the soffit. Overhang will help in addition, but I see a lot of cases where the drip edge is omitted or crushed and the result is faster rotting of the building.

Rural

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Re: why *wouldn't* you have a roof overhang?
« Reply #8 on: July 18, 2018, 08:08:27 PM »
Less wind uplift :) but that is proportional to overhang length, so if you only have a small overhang that seems purely beneficial. Or, if you live in a stone house with a fire resistant stone roof, like a castle, maybe.


I live in a "stone" (poured concrete) house with a metal roof and love our 2 foot overhang. It allows passive solar heating for much of the winter, too.

Radagast

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Re: why *wouldn't* you have a roof overhang?
« Reply #9 on: July 18, 2018, 09:57:23 PM »
Less wind uplift :) but that is proportional to overhang length, so if you only have a small overhang that seems purely beneficial. Or, if you live in a stone house with a fire resistant stone roof, like a castle, maybe.


I live in a "stone" (poured concrete) house with a metal roof and love our 2 foot overhang. It allows passive solar heating for much of the winter, too.
Metal not stone cheater :D but an insulated concrete form house is probably my dream house.

Trifele

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Re: why *wouldn't* you have a roof overhang?
« Reply #10 on: July 19, 2018, 09:35:58 AM »
Amen on the overhangs.  We are in the end stages of re-building our house (including a complete roof rebuild including all rafters) and we went with three foot overhangs.  For our location and the structure of the house that should be ideal for passive solar purposes.   As someone mentioned upthread, it does create an issue with potential uplift in windy weather.  We don't live in an area with dangerous weather, but because we never wanted to worry about it we put in metal hurricane strapping as we built the roof.  Should do the trick.

Rural

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Re: why *wouldn't* you have a roof overhang?
« Reply #11 on: July 19, 2018, 10:34:00 PM »
Amen on the overhangs.  We are in the end stages of re-building our house (including a complete roof rebuild including all rafters) and we went with three foot overhangs.  For our location and the structure of the house that should be ideal for passive solar purposes.   As someone mentioned upthread, it does create an issue with potential uplift in windy weather.  We don't live in an area with dangerous weather, but because we never wanted to worry about it we put in metal hurricane strapping as we built the roof.  Should do the trick.


Yeah, we put hurricane straps on ours, too. Cheap and easy while you're building anyway.