Soft roof, is that a problem?

Old 04-07-02, 09:57 AM
ME Wolf
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Question Soft roof, is that a problem?

I bought a house that is about 30yrs old. The roof is about 4yrs. old. When I walk on the roof it feels soft, kinda spongy. Why is that? The entire roof feels like that. The house is a ranch. The roof has about a 35 degree slant to it. The shingles look like they are in good shape. They are the type with the little stones inbedded in them. We have lived here a year and it has never leaked. Today when I walked on it I heard a snaping sound in one place when I put my foot down. It worried me that the board under me was breaking! It it normal for a roof to feel soft?

Old 04-07-02, 11:27 AM
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No... it is not normal for your roof to feel spongy. You stated that it has a new roof on it ,Was the original roof removed and this roof installed or was it layed over the existing? If it was removed and the new one installed the contractor should have noticed if the sheathing had dry rot which causes the sheathing to feel spongy and it should have been replaced at that time. You should look at the sheathing from your attic to see what condition it is in.
Old 04-07-02, 11:44 AM
HappyWoofer :-)
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Those "little stones" are ceramic granules/very heat resistant! There are diff possible reasons for the softness!
1.How many layers are on the roof-Up here in Toronto there soon may be changes to the building bylaws that will change roofing standards-if the roof joists are 24" centers then only 1 layer will be allowed on the roof-they are finding the weight of 2 layers is too much for today's building standards.
2.If you do have 24" centers and the roof was stripped the "H" hooks(between 24" centers-small silver plates can be seen in between joists in attic at edge of plywood/OSB)may have been accidently removed-these H hooks make up for the lack of proper roof joist support.
3.Is your roof deck OSB or plywood-This is a VERY controversial topic but I do not believe OSB is proper support for a roof.
4.Is your ventilation adequate-do you have ac but is your home still hot in the summer?-trapped hot moist attic air will warp OSB/plywood.
In the attic area is your soffit vent area open to the attic area(clear of insulation)ensures good air flow to the roof vents.
5.Previous owners may have waited too long for roof replacement.
I would suggest you go into the attic and take a look at:
- Soffit vent area-should be space between roof deck/insul for air flow.
-Check the area where you heard the wood break.
-Check for 24" or 16" joist centers and check for H hooks.
-Is the underside of the roof deck water stained-damage from old roof leaking?
One last point in regards to previous owner replacing roof too late-the steeper the roof,the longer the shingles will last-it seems your roof is not steep and therefore shingles cannot be expected to last as long-it may be 4/12 pitch-anything below this is low-slope which requires special installation procedures/materials.I'm sure there will be info that others on this board will be able to bring to your attention.

Woof :-)
Old 04-07-02, 09:24 PM
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The ceramic coated granules (little stones) are not for heat resistance their main purpose is to keep UV rays from baking the oils out of the asphalt shingles and causing premature deterioration to the shingle mat. OSB came on the market in 1980 and if your home is 30 years old it most likely will have 1/2 inch plywood sheathing installed over 24 inch on center rafters with no H-clips again this method is not 30 years old. Plywood 30 years old may have dry rot because of the lack of proper ventilation which again was not concidered to be much of a concern 30 years ago.
Old 04-08-02, 03:42 AM
ME Wolf
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Thanks roofrat, HappyWoofer,

I will check out all those suggestions. I know the soffets are vented to the attic, but I've never checked to see if they were clear or not. Also not sure if there is enough venting. Thanks for the advice.


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