# Foam is expensive



## Tochsia361 (Jul 7, 2015)

I originally wanted to remove my blown in insulation in the attic and get spray foam insulation however the price has since deterred me from that route. I know foam is the best you can get right now but..... I am wondering how this would work. Rolled foil insulation with tape for the seams on the rafters leaving air gap between the foil and roof decking material of course the gaps would be full width of the ceiling rafters as the foil would be secured to the opposite side inside as the roof decking sheets outside. Sheets of plywood over ceiling joists with caulk and or tape for seams and rolled or sheets of prefab insulation board with tape over the plywood sheets of course leaving the old blown in insulation in place which is still in good shape. I have a ridge vent ventilation system so would I need to add powered fans for extra ventilation? I think this would be cheaper than the 6k foam job. 
Anyone that reads please chime in as I am a complete novice looking for advice and thank you in advance .


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## craig11152 (Jun 20, 2015)

how much space are you talking about? Are you trying to save on heating? AC? or both? How much are your current bills roughly? sometimes people get over the top with things and eventually find the payback is 150 years. JMO. 
Why not just blow in more insulation?


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## Tochsia361 (Jul 7, 2015)

House is apx 2600 so just guessing attic 1500? We just moved into the house so not sure on bills. I don't think any of them will be out of control


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## joecaption (Nov 30, 2011)

http://www.energystar.gov/index.cfm?c=home_sealing.hm_improvement_insulation_table
Not getting any of what you suggested.
I'm with Craig, if there's not enough insulation then just add more blown in, just make sure not to block the soffet vents, may need to add foam baffles.


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## Tochsia361 (Jul 7, 2015)

Like I said, complete novice here looking for experienced advice. And thank yall for it! Looks like adding blown in will be the way to go. Just one more question if yall can indulge me. How much does adding a covered deck around your home help with keeping it cool?


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## Windows on Wash (Aug 30, 2011)

Is your attic conditioned or vented?


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## craig11152 (Jun 20, 2015)

> I have a ridge vent ventilation system so would I need to add powered fans for extra ventilation?


Do not mix and match exhaust venting. Air follows the path of least resistance and when the power fan kicks on the ridge vent becomes an intake which it is NOT designed to be.


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## Gary in WA (Mar 11, 2009)

If you need more insulation, add some blown cellulose (or high-density FG) rather than more low-density fiberglass as it looses heat due to inherent convective looping. Or add some more, then a housewrap cover over it all to get same end results- stop the convective loops. 

Welcome to the forum!

"How much does adding a covered deck around your home help with keeping it cool?" ---- On a southern exposure it may well even-out as the solar gain of the asphalt roof will warm the second-story siding/soffit vents to attic, IMO. 

Gary


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## jogr (Jul 24, 2007)

If you put foam board above the loose fiberglass then you will have added a moisture barrier on the wrong side of the fiberglass. This could cause condensation that will wet your loose fiberglass and cause mold issues. The foam would have to be thick enough that the dew point is not reached on the bottom surface of it. 

I have even seen condensation issues just with putting a plywood panel over the top of fiberglass for attic storage.


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## b-boy (Feb 28, 2007)

I have a deck that wraps around 2 sides of my house. It on the South and East sides of the house. It does a pretty good job of keeping the first floor cool. The house has no A/C.


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