I have an old home and I want to insulate the cellar ceiling. I am thinking the easiest way would be to have it spray foamed. What happens to all the electrical wires that. Will become buried underneath it when done? Is there an issue here or not?
Spray foam
- Thread starter Jeff Lary
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NSMaple1
Addicted to ArboristSite
I don't think I would bury wires in foam.
No data to back that up - just a feeling.
No data to back that up - just a feeling.
Just don't bury any junction boxes , wires are fine.
Yup. Bury wires, not boxes. Spray is the best.
Kind of what I figured I really have no other options that are practical. My cellar celling joists are logs about 6 feet apart. Very old home. Thanks for the opinions
Wowzer
ArboristSite Operative
My buddy just looked into spray his shop. That has steel on studs. And the company said to poly it. And then spray and he had BX wire in his shop and they said that you can spray over the new house wire. But not the BX and older the aluminum stuff. They said that there's a good chance it will corde
Make sure you go with closed cell poly.
ok
ChoppyChoppy
Tree Freak
Open cell won't trap water. Ruined a whole building's roof from closed cell. Roof keaked, took years to notice, rotted it out BAD. I'm talking rotted out thev1" sheathing and rafters bad.
Closed cell is simply the best bang for the buck. It has a higher R value per inch than closed cell. The statement about causing a roof to rot is misleading, they obviously had a faulty roof system for it to leak in the first place. Closed cell also adds structural rigidity. Just my .02, it's one of those products that just keeps paying you back year after year.
ETA; I have been a builder for 40 years, I consider myself a professional.
ETA; I have been a builder for 40 years, I consider myself a professional.
ChoppyChoppy
Tree Freak
No, it's correct. Like I said, roof leaked and the closed cell foam trapped the water. Because of that it went unnoticed for at least 5 years, probably longer before it was noticied.
Anthem section if the building just was bat insulation, a re-reroof fixed it, no rot.
NSMaple1
Addicted to ArboristSite
Would open cell have really prevented it though? Thinking it might have sponged up - then maybe wicked down into the walls, possibly unoticed also, and made more damage?
Been thinking about this too, for the basement & possible summer project there. Likely will do 4x8 sheets.
Been thinking about this too, for the basement & possible summer project there. Likely will do 4x8 sheets.
There will be no cell in my cellar just foam too many things on the celling to try to put plastic around .It will get sprayed,.. or nothing I think.
So....my 2 cents and I used to own a spray foam business and have a lot of hours spraying and learning about house science to make sure I never screwed over a customer.
open cell does trap water....the skin will act as a little moisture barrier but the inside will suck up water and that is why I cautioned people not to use it in areas that could leak (like metal buildings)
I roof failure attributed to closed cell is not a real thing unless the foam was not at the right temp or mixing ratio between A and B sides when sprayed......this would cause it not to bond to the substrate and create voids which would hold moisture and would assist the roof in failing if those voids were in the same area as the beams or decking (large voids).
Properly applied, closed cell spray foam is a complete moisture barrier at 2" depth and as the foam expands it will fill all the tiny holes that would have leaked and actually prevent roof failure while also adding structural integrity to the substrate ...2" is said to have 75% racking strength of 5/8th plywood.
open cell does trap water....the skin will act as a little moisture barrier but the inside will suck up water and that is why I cautioned people not to use it in areas that could leak (like metal buildings)
I roof failure attributed to closed cell is not a real thing unless the foam was not at the right temp or mixing ratio between A and B sides when sprayed......this would cause it not to bond to the substrate and create voids which would hold moisture and would assist the roof in failing if those voids were in the same area as the beams or decking (large voids).
Properly applied, closed cell spray foam is a complete moisture barrier at 2" depth and as the foam expands it will fill all the tiny holes that would have leaked and actually prevent roof failure while also adding structural integrity to the substrate ...2" is said to have 75% racking strength of 5/8th plywood.
So like I said being that the celling in our cellar is really just the sub floor of the first floor I thought spray foam would be a good way to go. The celling has a lot of pex tubing and wires some old but mostly new stuff. We removed all the copper a while back when we did an on demand gas water heater, and replaced it with pex. So there is barely a square foot without either wires or plumbing of ductwork for our back up forced hot air furnace. I heat solely with wood but if we have to be away in cold weather we run the oil furnace.
The floor in my living room in the corner where I sit is maybe 40* - 50* if it is real cold outside like single numbers or below zero. That cold kind of wells up in that area and other outside wall areas. My chair is in a corner where 2 outside walls meet.
The cellar is in-heated of course. Great for vegetables like, potatoes , carrots, and a 10 gallon crock full of salt pork. This welling upwards of cold air is tolerable but not welcome. I am hoping if they can spray 4-10 inches of foam up on the cellar celling that would make a giant difference in room temperature. The living room is most noticeable but the kitchen near the outside wall is just as bad.
The floor in my living room in the corner where I sit is maybe 40* - 50* if it is real cold outside like single numbers or below zero. That cold kind of wells up in that area and other outside wall areas. My chair is in a corner where 2 outside walls meet.
The cellar is in-heated of course. Great for vegetables like, potatoes , carrots, and a 10 gallon crock full of salt pork. This welling upwards of cold air is tolerable but not welcome. I am hoping if they can spray 4-10 inches of foam up on the cellar celling that would make a giant difference in room temperature. The living room is most noticeable but the kitchen near the outside wall is just as bad.
NSMaple1
Addicted to ArboristSite
Your veggies might freeze. Maybe pipes too. Can't tell by reading though.
What are the walls of this cavity like? Likely cold air is coming in through there? Can you get those sprayed instead?
What are the walls of this cavity like? Likely cold air is coming in through there? Can you get those sprayed instead?
If you have a good solid no leak floor you can go with 6 to 8 inches of open cell foam (any more than 8 inches really does not give you much more effective R-value) but you will have to get a diligent sprayer that takes the time to get between the pipes and the ceiling so he does not create bridges (voids) where the foam expands. Open cell would allow you to easily cut or rip out sections to do repairs (electric or water)......your pipes will not freeze if encapsulated and heat generally rises so if your vegetables are not freezing now that will not change
If you go closed cell....then put on no more than 3 inches....anything more than that will only increase effective insulative value from say 95% to 96% so not worth the cost
it is much harder to cut out if needed so make sure you are real happy with what you got now.
walls---- there are systems that do injection foam by cutting holes in the top of walls and then spraying inside ....costly and only works if there is no insulation in the walls so you would have to remove the paneling/sheet rock or whatever is the outside paneling to get to the old insulation and remove it and then spray
I have always told people that walls were the last to consider spraying if cost was an issue...think of all the doors and windows that have very low R-value....work on sealing those well and that will make a cheap difference. If you do consider injection foam they will have to have a thermal imager to see where the voids are, so you will know what is there before they start cutting and for piece of mind a home energy auditor would have one too....if you have nothing in the walls...you need to fix that.
Code.....most home owners don't care about code but... foam is plastic and plastic burns at a lower temp than walls, floors, roof ect. so foam is not supposed to be left "wild" if there are people around
two standards....5 minute barrier (ignition barrier) for places that people do not usually go (attic with no storage) most closed cells are rated for this and open cell needs a spray on (thin layer) ignition barrier
when people are around.....15 minute barrier ....sheet rock, most paneling and metal panels are considered a 15 minute barrier or a much thicker coat of the spray on barrier which adds another $1 a sq ft or more to the price....but insurance guys will not be able to say the the foam increased the fire damage and screw you
If you go closed cell....then put on no more than 3 inches....anything more than that will only increase effective insulative value from say 95% to 96% so not worth the cost
it is much harder to cut out if needed so make sure you are real happy with what you got now.
walls---- there are systems that do injection foam by cutting holes in the top of walls and then spraying inside ....costly and only works if there is no insulation in the walls so you would have to remove the paneling/sheet rock or whatever is the outside paneling to get to the old insulation and remove it and then spray
I have always told people that walls were the last to consider spraying if cost was an issue...think of all the doors and windows that have very low R-value....work on sealing those well and that will make a cheap difference. If you do consider injection foam they will have to have a thermal imager to see where the voids are, so you will know what is there before they start cutting and for piece of mind a home energy auditor would have one too....if you have nothing in the walls...you need to fix that.
Code.....most home owners don't care about code but... foam is plastic and plastic burns at a lower temp than walls, floors, roof ect. so foam is not supposed to be left "wild" if there are people around
two standards....5 minute barrier (ignition barrier) for places that people do not usually go (attic with no storage) most closed cells are rated for this and open cell needs a spray on (thin layer) ignition barrier
when people are around.....15 minute barrier ....sheet rock, most paneling and metal panels are considered a 15 minute barrier or a much thicker coat of the spray on barrier which adds another $1 a sq ft or more to the price....but insurance guys will not be able to say the the foam increased the fire damage and screw you
brenndatomu
Hey you woodchucks, quit chucking my wood!
I had this done...the foam that was used was known to shrink 2% as it cured...I thought 2% is nothing, wrong. Do the math, 2% on a 16" stud cavity leaves a pretty good gap...so much for air sealing! Wish I had used this instead http://r.search.yahoo.com/_ylt=A0LE...ete.com//RK=0/RS=gbj2SsXXhxY1Sz0yy2RlACBhPn4-
Not that this helps OP any...just FYI on the spray foam topic...
I never put much stock in the injection foam .....as I understand it, it is mixed to expand slowly so it does not overfill the cavity which could account for the shrinkage which does not occur in most half, 2 and 3 pound foam..... with all the holes cut in the walls it would make more sense to bite the bullet and remove the sheeting and do it right (if there is no insulation at all in the walls)
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