Huge problem with Insulation in Cape style
SO Last year I had major Ice Damns with all that snow, the roof leaked and mold was discovered in teh crawl space on the front roof slop of my cap code style house. Due to improper instalation of insulation. Had the mold remediated, and had severl contractors with different opinions on how to re-insulate and ventilate the crawl space and the small attic above.
Went with a cotractor who installed Spray Foam insualtion in the soffit and up the roof deck on the front of teh entire house to "seal the area like an envelop". He felt this was the best option as part of the wall had built ins and this way he couls insulate behond it. He also installed soffit vents along back side of the house for ventilation.
Fast forward one year.... New mold was discovered in the attic area, most likely the emergency/mold company failed to notce that the roof leak also affected this area, the moisture remained and now new mold. They say the have to remediate mold, and remove 2 the feet celulose insulation. OK
Now During the same week, we got our first substantial snowfall. I am watching the snow melt from the top of my roof line right up to where the end of the foam insualtion ends. Obviously this is going to create a new ice damn at that point which is well above the water and ice barrier. The contractor said he did nothing wrong, The house has heat leakage in th attic that needs to be addressed. I now know we should have went with soffit and baffle vents and only insulated the interior walls, but now it is too late... It would be near impossile to remove the spray insualtion.
Does anyone have ANY ideas on what I should do when they put this all back togehter? I need to get that attic area ventilated and cold on the front top half of the roof slope.
I'm having a hard time picturing what you trying to expain.
How about a picture.
Is this living space or just an attic?
What insulation type, and how thick is it behind the knee walls.
What's on the back side of the knee walls?
Ah yes, the classic case of the spray foam cure all.
It is tough to tell what the recommendation would be in this case without a better description of the layout, what was done, and/or some pictures.
If you brought a kneewall into the envelope but eliminated the soffit air to the upper roof, that is a huge mistake. Is that what was done?
Yes that is exactly what was done......
This is a drawing of he side view of house
Here is the best drawing I can do of the side view of the house
you need more soffit vents in the attic.
he should have sprayed the knee wall and th floor not the underside of the roof and the soffit.
so you think it is feasable to put larger or continuos soffit vents in the back of the house and maybe a larger ridge vent to allow more cold air in and hot air to escape.
Did you see my drawing?
Do you think more vents in the back of the house will create enough air flow to keep the front attic ceiling cold?
Since I can not undo what was done, would you consider removing all of the insulation and spray foaming the entire roof deck? (that is one remedy someone has suggested)
1. How thick is the SPF?
2. Asphalt shingles? Light or dark color?
3. Is it air sealed under the knee wall?
4. Is there HVAC in attic?
5. Where are you located?
answers to questions from gary
The SPF fills in the joists.
Asphalt dark color
Air sealed under knee wall? Most likely not
No HVAC in attic
I am in Massachusetts
Your :censored: spray foam contractor monkeyed up your roof ventilation and design.
Big N8 is dead on.
Call that joker back and tell him he is on the hook for the roof and leaks.
The spray foam needs to be removed from the soffits and the underside of the roof where it meets the kneewall.
The kneewall should have been foamed as Big N8 says and the joists underneath the kneewall should have been blocker'ed and sealed.
Adding more vents is fine if you want to add them midway up the roof where the roof meets the kneewall with something like a shingle over vent (http://www.airvent.com/homeowner/pro...-theedge.shtml).
I would tell the contractor he is on the hook and make him fix it.
The roof hasnt leaked yet, I jsut know it is going to. we had one small snow storm and I could see the potential for the probelm at midway up the roof. Fortunatly the temperatures stayed warm and the snow melted, but I could see how the snow formed little damns already.... I took many pictures.
There is going to be no way to remove the foam unless I take the roof off, given the construction of the house and built ins in the kneww all etc.
The contractor is insisting he did nothing wrong,t here was no way to put in baffles to get the ait from the soffit.
But now he wants to put on a larger ridge vent, and more soffit vents on the back roof to get more air flow. Or remove emerything and do icynene. I dont want him back in my house to be honest with you....
Is that vent you mentionted something that can go under the shingles? Was your thought that I could put it above the foam in the roof line to get the air on that part of the roof and leave the foam?
I have my original roofer coming today so hopefully...
By building inspector, do you mean the town building inspector, or someone who inspects home when youa re sellign them etc?
If I could get that money back, it would at least help reduce the cost of what it is going to take to fix it!
That or a roofer that understands ventilation.
The spray foam contractor basically UN-engineered what was a working system.
Without the questions asked, I couldn’t establish if your SPF could still cause you diffusion problems adding mold to the sheathing for your location by just leaving it in place. According to science, you are fine because of the thickness; see the chart for your Zone 5A- same as Chicago--- if only 2” thick and high indoor humidity- you would be at risk: http://www.buildingscience.com/docum...d-roof-systems
1. Do you know the brand name of the ridge vent, or does your roofer know the NFVA of it? This would tell you if a larger vent is required….
2. Describe the existing soffit venting.
3. He SPF the entire ½ roof (including the slope ceiling) and where is the cellulose with the mold located? In that small knee wall attic? He was correct in SPF of that whole side, so long as the attic air cannot reach the small attic space. Did he block/spray the top edge of the SPF sloped ceiling, air-tight? Is the rest of the attic ventilated enough: http://www.airvent.com/homeowner/pro...it-specs.shtml
4. Does the cellulose have attic air above it (vented) everywhere it is installed?
“I am watching the snow melt from the top of my roof line right up to where the end of the foam insualtion ends. Obviously this is going to create a new ice damn at that point which is well above the water and ice barrier. The contractor said he did nothing wrong, The house has heat leakage in th attic that needs to be addressed.”-------
The ice dams/snow melt are from not air sealing the attic floor before installing the existing insulation. http://www.buildingscience.com/docum...d-135-ice-dams
For other readers: http://www.wag-aic.org/1999/WAG_99_baker.pdf
“The contractor said he did nothing wrong, The house has heat leakage in th attic that needs to be addressed.”-------
Correct. He did SPF the roof deck to create a “conditioned attic”; Fig.2, see chart: http://www.buildingscience.com/docum...rchterm=attic+
He was right-on with the warning he gave, did you do anything with the air sealing?
Your SPF installation is correct, leave it alone. You need to air-seal under the cellulose to stop the air leaks by chases/elect./plumbing holes vs. diffusion: pp.17 in article: http://www.buildingscience.com/docum...researchreport
Ideally, you would have discussed air sealing and had him do that as well as under the knee walls with SPF when present; http://www.familyhandyman.com/DIY-Pr...s/Step-By-Step
I can’t stress the importance of air-sealing enough: http://www.greenbuildingadvisor.com/...stop-air-leaks
Have your roofer fix the roof leaks and do a quality inspection of the whole roof, (also check your NFVA), as you learned- any leak on the cellulose from above without enough ventilation will mold.
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