mineral wool or glass insulation?????

[Tarheel Slim]

Im at the point where in ready to insulate my 30 x 44 pole barn,i have white EPS foam tapped up with red tape in between the perlins and now i would like to add insulation,im using 2x4 for framing in between the posts ,im wondering if i use insulation made for 2x6 framing if that would be better than having a gap between the EPS and the backside of the insulation.Does the insulation have to be tight against the EPS foam ? If i use regular 3.5 inch glass insulation made for 2x4 framing would that be ok too?Also thinking of using 24 inch spacing for the insulation although im not sure what i will choose at this point,i had Roxul insulation in my last shop it worked great but i dont have the connection to buy it cheaply anymore so i need some input please guys,thanks.

 

[theoldwizard1]

... im using 2x4 for framing in between the posts ,im wondering if i use insulation made for 2x6 framing if that would be better than having a gap between the EPS and the backside of the insulation.Does the insulation have to be tight against the EPS foam ? If i use regular 3.5 inch glass insulation made for 2x4 framing would that be ok too?.

A gap between the 2 different types of insulation is actually beneficial IF they are both PERFECT air barriers. This means on the side you have finished you need to go around every place where your EPS meets wood and seal it with canned spray foam. (It would have been better if you did this first, but ... )

Mineral wool is usually more expensive that fiberglass, but to both need a vapor barrier on the interior side to complete the sealed wall.

"Dead" (non-moving) air is an excellent insulation. A vacuum is even better.

 

[DC73]

I like mineral wool better than fiberglass. It blocks the flow of air better, has better fire resistance, does a much better job of blocking the transmission of sound, and standard batts are R15 instead of R13. You can get R15 fiberglass but around here it has to be special ordered.

Check with some of the vendors that cater to builders. You might find a better price than the big box stores. One option for me was 84 Lumber. When I was insulating my shop, they beat Lowe's price on Roxul by 20%. It was still more expensive than fiberglass but it was worth it to me.

DC

 

[Tarheel Slim]

Posting a pic to show where im at roughly,im also going to partition off a wall to have a 320 sqft. for my tools, lathe and mill also hang out area with wood stove,im thinking about making my own sliding wood Z frame barn type door and insulate it when i build the partition wall,i dont want to frame a swinging double door,like to stick with something more rustic looking,concerned about how well it will seal though.I will take some more recent pics today.

 

[Tarheel Slim]

Here are a few more pics,should i use fiberglass to insulate my walls or spend the extra cash on some Roxul mineral wool. Im also thinking it would be wise to have insulation the full depth of my 6x6 posts which are 5.5 inch.rather than stuff made for 2x4 framing,i could still use 2x4 framing for the insulation made for 2x6 i would have 3.5 inch depth holding the 5 inch thick insulation in place,can anyone see a problem with this ???

 

[Crazyjake8493]

I like mineral wool better than fiberglass. It blocks the flow of air better, has better fire resistance, does a much better job of blocking the transmission of sound, and standard batts are R15 instead of R13. You can get R15 fiberglass but around here it has to be special ordered.

I agree! Mineral wool is so much nicer to work with than fiberglass, and superior in almost every aspect except cost. It's much easier to cut out around wiring and boxes, anything like that.