I’m getting ready to do my vinyl siding on my entire house and am wondering what’s the best insulation or shelter wrap I should use underneathe it? I was going to go with 4×8 sheets of 1/2″ rigid insulation board, but at $12.68 each (@ Depot) its gonna hit me for almost a grand to do my entire house. (I will need 75 sheets of it) There was some other 4×8 insulation which was white and looked just like regular sheets of 1/2″ styrofoam for a little over $6 each. Anybody have any experience with this product? Or I can go with regular 3/8″ fanfold at about $43 per 200 s.f. Any other suggestions? What do you use? This is my house so I want to do it right……..
Craig
Replies
My favorite foam is the foil faced stuff. 3/4" thick.
I have been siding houses with it under it for a few years and it makes a difference. I have built a few homes for my dad and one had it the other one didn't. The one that did outperformed the other by 15% decrease in heating costs.
Paid for itself after 2 winters. If new construction build out your RO's with 1x then nail your windows into them. Then foam up to the 1x. Using spray foam to fill and seal any voids.
What the problem is?
would you need to take all the seams to make an air barrier or do you use a housewrap over it?
No house wrap, the sheets I get have a tongue and groove kind of set up. Like a half round knuckle joint.
Just hang all the pieces the same way so the joints interlock well and it's better than any housewrap.
What the problem is?
I'm using it under my 'Cedar Impressions' and I'll vouch for the heat loss savings, but make sure it's treated with Borax or something compatible...thanx to MikeSmith for that tip.
As for the 1x buildup of the RO, won't that require jamb extensions on the interior?
Yes it will. But without them you are nailing your windows into foam.
Just order your windows with wider extension jambs. Easy fix.
Be sure what is treated with Borax?
What the problem is?
Edited 9/11/2006 11:32 pm ET by Stilletto
the foil faced insulation...
for pest control
"But without them you are nailing your windows into foam"
That much I understand, but why not nail the window to the sheathing and then butt the 3/4" insul to the window? Or picture frame the window with 1x and butt the insul to that. The only limitation to either of those would be the amount of protrusion of the exterior window jamb...meaning too shallow of a protrusion would give a sunk in window appearance
I would set my windows flush with the exterior unless you're planning on some pretty elaborate flashing.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
I agree and I guess I was trying to say the same thing...I was going to go back and edit it some, but I figured he knew what I meant
but what really confused me is what was stilleto trying to accomplish by doing it his way? The only thing I could come up with is he wants to use the 3/4 insul under the siding without the windows being recessed...a 'sunk in' look effect like you get with multiple siding overlays and leaving the windows nailed to the sheathing.
make sense??
Most of my windows have the j-channel already molded into the window frame, so I have to mount the windows this way. I am not going to pay for j-channel when it already comes molded into the frame.
What the problem is?
makes sense
Here's a suggestionfor a cleaner look on vinyl siding. When using windows with a J channel extruded into the frame, cut an additional piece of J channel that matches the siding that you are putting up. This helps blend the siding into the window frame and you will not tend to see every end of the siding in the white channel.
It does take a little of time ripping the front round over off the J channel on a table saw and with it cut to the right width, it snaps into place behind the window frame with only one or two screws holding it in place
Thats a very small detail that I have never had to address with vinyl siding. So keep that one to yourself. :)
Most of the jobs the windows match the trim color of the house. Looks like it's supposed to be that way.
As for J-channel on a table saw, no thanks. I would score it with a utility knife and snap it off. The stuff is only 1" wide, to small for a table saw. If it were more rigid maybe.
BTW where are you talking about putting the screws? I hope not into the window, but into the sheeting. And roofing nails would do the job just fine.
What the problem is?
Are you concerned with the vapor retarder that you're creating on the outside with the foil? I would assume in MI that you use poly on the interior side. I think this would be an invitation for problems.
Jon Blakemore RappahannockINC.com Fredericksburg, VA
I haven't seen poly used in this area for years. Maybe 15 or so.
What the problem is?
As often as that concern of foam board on the exterior siding creating a double vapor barrier being bought up, I have never yetseen an answer worthy of note.
Seems done often enough without known problems but perhaps they are just quietly lying in wait as the years progress and gathering steam for an explosive escape into known builder snafus.
A bird does not sing because it has an answer. A bird sings because it has a song.
All of the above.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
Here's my experience with using foil faced board...
I started my siding job back in 97/98 and soon after I discovered some sheen problems with the vinyl Cedar Impressions I was using. I hung about 10 sq before Certainteed acknowledged the problem and covered everything under warranty...my labor and all the materials. I continued on another side of the house using the new stuff and planned to go back and replace the 10 sq at a later date.
In 04 I gutted my kitchen right down to the studs, whcih has one exterior wall that was covered with part of that bad 10 sq. Other than some minor window leaks in the lbottom corners, no other signs of dampness was found. Even the sill plate in every stud bay was spotless. Same goes for the FG insul in the stud bays...I removed all of that too.
Last year I stripped that same exterior wall on the outside right down to the sheathing to remove the windows and correct the leaks, and hang the new siding. Again...other than some stains on the sheathing at the bottom of the windows, everything was in the same condition as I last saw it in 97. Not one bit of moisture damage anywhere. The 3/4 foil faced(both sides) I'm using is perforated on one side and maybe that's why there was no moisture problems?
So IMO...using the foil faced hasn't caused any problems and I have some pretty good proof of it. We get pretty cold winters here in CT and I would think if it was an issue, I would have seen something. Maybe after 20 yrs or so it might be an issue, but I doubt it.
Edited 9/12/2006 4:34 pm ET by caveman
That's pretty good news, especially concerning the FG insulation which always seems to be the first thing to act as a sponge.
be bet you were a happy camper
A bird does not sing because it has an answer. A bird sings because it has a song.
I'm building now and am using foam on the outside and wondered if I should pult my tyveck on before or after foam. Already have the tyvek (free) and celulose will be the insulation.
again, what side should face out? the side with the lettering on it or the reflective side? I haven't seen rigid insulation around here that has foil on both sides and is perforated. The stuff at Home Depot is foil on one side and blue with lettering on the other. So which side out?
Craig
Probably the lettering should face out, but maybe either way??
Without seeing it, hard to say for sure. Got a pic? or a link?
Common practice seems to be face out and upside-down.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
no doubt there...
;)
Best check beneath the lettering as some of those foilbacked foam board manufactures have foil on both sides with one side of the foil being covered with the plastic liner.
A bird does not sing because it has an answer. A bird sings because it has a song.
I was always told that the foil face points out. Foil side towards the airspace.
What the problem is?
"Foil side towards the airspace."
suppose he has a rain screen wall? :@)
I am assuming that he used sheathing on his walls.
Well either way the airspace is out. Either insulation on the inside or sheathing there wouldn't be an air space.
I think I know what foam he is using, blue on one side foil on the other. I used it in the ceiling of my house. Can't remember the manufacturer of it.
1/2" thick and if an airspace is provided it's supposed to have the R-value of 3/4" foam, or a little higher.
What the problem is?
I was just being a wise azz...;)
but in defense...there's also an airspace for drainage in rainscreen walls.
My favorite foam is the foil faced stuff. 3/4" thick.
Out here in Nebraska our supplier says that the vinyl siding manufacturer does not warranty vinyl installed over foil face. Something about the foil reflecting to much heat on the hot sides and wrinkling the vinyl. I never checked it out beyond their word for it and just always use the pink stuff. You been using the foil for a while now with no problems ? Maybe they just wanted to sell the pricey stuff to me........ =)
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specializtion is for insects. - robert heinlen
First house I sided with it under it was 14-15 years ago. Celotex brand I believe.
I was 13 yrs old and sided the house with my grandpa and uncles. We lived in the house for 5 years and no problems when we left.
Edit: I have also used the blue foam with good success. Building out my openings and using 1x for the bottom to nail my starter on.
If the manufacturer says not to use foil faced then listen to them, don't listen to some whack job carpenter on the internet. :)
What the problem is?
Edited 9/12/2006 9:00 am ET by Stilletto
If I use the 3/4" foam, which side is out?, The reflective foil side or the side with the lettering?
Craig
Here in Canada, standard construction is poly vapor barrier on the inside, insulated walls, 1" pink foamboards over the outside with all joints taped, then tyvek, then siding of your choice.
The product I use has foil on both sides
Is one side perforated?
"Something about the foil reflecting to much heat on the hot sides and wrinkling the vinyl."
I used the 3/4 foil faced under the siding, and on the south wall of my place it hits 130*+(surface temp) in the summer and no wrinkle problem . IIRC Certainteed Cedar Impressions is about .100 thick and that could be why. Warranty isn't voided either. Maybe just an issue with the thinner grade products
edit...excuse the double post<G> I deleted it. I had to close the browser and didn't think this one went through
Edited 9/12/2006 11:38 pm ET by caveman
The purpose of the fan-fold stuff is to provide a flat surface when overlaying existing siding -- it provides relatively little extra insulation, and is a lousy wind barrier.
So the first question should be: What're you gonna put the stuff over? Are you ripping off existing siding or leaving it there? What's the state of your existing insulation? How old/tight is the house?
On Long Island I suspect that reducing air infiltration will buy you more in terms of comfort and energy savings than more insulation will.
Craig - I have no opinion about your original question, but I would like to congratulate you on spelling "vinyl" correctly, which is seldom done on this forum. And, I've probably spelled several words in this post incorestly, I mean wrong.
"Let's go to Memphis in the meantime, baby" - John Hiatt.
http://grantlogan.net/
I'd tyvek the house then use Cranboard siding with the foam already laminated on it.
The first contractor I worked for some 26 years ago always put the foam board on the INSIDE of the house, reflective side in.(course it was reflective on both sides) sure stiffened up the drywall, had to use longer screws and nails but it was all good.
I did my shop this way, with plywood instead of drywall, and 1" foam over the studs with R-19 FG, ply sheathing, tyvek and craneboard siding.. should be R-30 or close. Feels warm in the winter being heated by a Woodmaster outside boiler.
Not to Hijack CB's thread, but . . .I am planning a reside in the spring. Is it worth it to add foam to an existing structure and go to the effort of extending the windows jambs and everything? I plan to replace 5 windows and reside with vinyl. I'm not sure what's there now, but on a cold day, the stud lines telegraph through the existing siding. I planned on adding housewrap at a minimum, but wasn't sure if it would pay to add foam, then wrap and side. I figure I would lose an inch of overhang, but can probably live with that if I get greater energy efficiency.
greater energy efficiency
yep.
A bird does not sing because it has an answer. A bird sings because it has a song.
Hey guys I went on the DOW website (DOWbuildingmaterials.com) and they said the rigid insulation should go on with the blue side or lettered side facing out. They did say that both sides are really foil faced so it doesn't really matter, they recommended that with the blue lettered side out the glare wouldn't be as bad when you begin putting the siding on and hey if you leave it exposed for some time it really is free advertising for them. Ha ha. They also said you should put the boards up vertically instead of horizontally, but it really doesn't matter much either.
happy building,
Craigabooey
Sounds like you got the answer you needed, which is what matters most. Glad to hear it and have fun...
btw... here's a tip about the foil face glare: if you are working in direct sunlight in front of it, be forewarned about the reflection. It'll make you look like a RED LOBSTER if you don't take precautions.
Don't ask me how I know<G>