Need Insulation Advice For New Shop

[monteu]

Hello to all: stumbled onto this forum and it looks interesting. I need some advice. I am building a 40 x 60 x 12 shed using Adams Trusses. These are clear span trusses. 40 x 30 of this is going to be enclosed and insulated. Now what insulation? Spray foam is extremely expensive, 1.90 per square. I know it is good. Thermax rigid board is expensive also. Rolled fiberglass insulation is the most economical or a foam type foil backed board. I do want it insulated, I will try to keep it around 60 degrees. I live in NE Kansas. What have some of you done and really liked for insulation? Thanks for your input

 

[Rustyiron]

Don't skimp on insulation! check out Welcome to Insulation Depot - Rigid Foam Insulation, Used Insulation, Roofing Supplies, Roofing Material and see of they have anything within a reasonable distance from you. I put a layer of tyvek under the metal and that is another cheap item that is worth it. Just because the steel siding keeps out the rain, you'd think that it would also keep out the wind, well not all of it. This is very important especially if you use FG. The R value drops like a rock with air movement thru it. I put 2 layers of ridgid poly iso. of 1.5", 3"total, and foamed all edges of each layer. (I got it from the guys at the above link) I have radiant heat in the slab and it works out real nice. The weak link is those dang seals on the overhead doors. There must be a better way to seal the doors, there's 120' of gap on 3 14x12 garage doors!

 

[Depmandog]

When I built my pole barn 42x68x14 with wood trusses, I used metal building insulation between the heavy gauge metal siding and wood framing. The insulation has an all service jacket.

Rips and tears can be repaired with ASJ tape. I bought mine at a insulation place off Van Brunt in KC called Superior Insulation several years ago. They cut the pieces to length, are 4' wide, and the jacket has an overlap. It's a full run - no cuts all the way across my roof - 45 feet or so.

It wasn't the easiest thing to install, but the building sure is warm. You have to install it as you put on the metal.

The only downside, keeping the mice from tearing it up. I have 3/4 ply on the inside of one corner where I have fence post, ect leaning in the corner. I will probably skin 8' up all around with the ply. It will be dual purpose, thieves cut through the metal, ripped the insulation and the alarm got them, but the ply would slow them down some. I hate thieves.

I don't know if Superior will sell to the public, I ordered it thru a building contractor that I know. But in this economy I doubt they tell anyone no (if they are still in business).

Dean

 

[KennyG]

If you are studding up interior walls at 16 or 24 centers, conventional fiberglas batts are best for that. For exterior walls you want something that spans between the posts, meaning something like polyiso foam. I was able to find good used polyiso sheets for $5 a sheet. Check with commercial roofing companies to see if they have some or know of a source. Polyiso is way superior to the home improvement foam.

The roof/ceiling is really important. If you are leaving the truss area open, you almost have to do something like spray on the underside of the roof steel. If you want a ceiling, you can attach interior steel panels to make the ceiling (to keep weight low) and blow cellulose above it.

Whatever you do, put a good vapor barrier on the inside of the insulation. I used 4 mil clear poly. It's pretty easy to work with.

 

[PAfarmer]

I spray foamed mine and its a huge building. I could almost heat it with a candle now. Expensive but it works a treat.

 

[Depmandog]

The roof/ceiling is really important. If you are leaving the truss area open, you almost have to do something like spray on the underside of the roof steel. If you want a ceiling, you can attach interior steel panels to make the ceiling (to keep weight low) and blow cellulose above it.

If you decide to add ANY weight to your trusses - ie adding a ceiling, etc., let your truss manufacturer know so the can design the added weight into the truss calculations.

Side note: Most of the time, your truss manufacturer is relatively local and will factor in snow loads, but if not local - make sure they know your geographic location. Everyone once and a while we get those plains blizzards and ice storms in this part of the country.

Dean

 

[monteu]

What is the difference between polyiso and polystyrene besides the price?

 

[Bigkrank]

I have a 42 X 45 and a 54 X 83. Both are insulated on the sidewalls with 6" fiberglass covered with painted OSB and ventilated soffit for noise control.

You can get rolls of insulation 7 1/2 feet wide to go between the posts. Ceilings are metal with fiberglass cubes blown in.

I helped a bullheaded buddy build a shop and pieced 24" wide fiberglass batts between the posts, what a joke.

Our Features - Energy Performer® Package by Morton Buildings, Inc.

i n.

 

[sawduster98]

I spray foamed mine and its a huge building. I could almost heat it with a candle now. Expensive but it works a treat.

Mine's not huge, 24x24x10 but also spray foamed. Best $$$ I spent. I use a 5kw electric heater set on its lowest setting to keep it around 60. Now I wish I'd done my whole house with it.

 

[KennyG]

What is the difference between polyiso and polystyrene besides the price?

Polyiso is a closed cell foam with very fine grain. It is much easier to work (cuts smooth), more durable and has, if I recall correctly, about twice the insulating value.

 

[Kyle241]

I'm planning on blown-in cellulose for my walls (24x32). Not certain what I am doing with the ceiling yet though as it may end up being a combination of some sort.

 

[forgeblast]

I would think about critter nests, the spray in will keep the mice etc out, while the fg batts give them a great place to live.

 

[Gary Fowler]

I dont like blown in insulation as it settles too much. In a year, you will have a void at the top. I have 6" bat in my house with 15" of blown in fiberglass on top when new and it is less than 12 after 1 1/2 years. I prefer the fiberglass batts or foam. I used the 6" R-19 bats in my shop in walls and ceiling with insulated garage doors and a 1500 watt heater will keep it as warm as you like. I have one in it now on low heat (750 watt) and with 25F outside this morning it is nice and warm inside and the heater thermostat had it cut off. I also have the reflective insulated boards under the galvalume roofing which helps keep it cooler in summer. I have it sealed in the ceiling(9' 8" height) and walls with 3/8' plywood inside and 1/2" exterior grade plywood outside so there is some insulating value to the wood compared to sheet metal siding or vinyl. Attached photo of shop with currently under construction 14 x 30 addition for boat/ lawnmower storage. I dont plan to insulate this portion right away, maybe later if it starts getting too hot in summer.

 

[wedge40]

No one asked but I will. What will the insulated area be used for and how do you plan on heating it? These two things will help decide how well to insulate.
My self I'm using radiant floor heat, spray foam and fiber glass on the walls, then fiberglass in the ceiling.

Wedge

 

[monteu]

It will be a metalworking shop. A place for a couple lathes. I am thinking I will use a radiant tube heater to heat it. I really don't need to keep it over 60 degrees. I guess I a little confused by my options. I can go fiberglass or spend 4x as much polyiso board or 7x as much for spray foam. The rollout fiberglass insulation that you put on between the purlins and sheet metal is so much more economical than anything else. Appreciate all the thougts so far.

 

[anojones]

There are some issues insulating a metal sided shop that will be heated, the warm air inside will allow water to vaporize and move through the insulation to the inside of the metal siding and condense there causing moisture (insulation can become wet etc). Moisture that does move through can get trapped in the insulation and along the walls. This is the great advantage of the spray on foam- no moisture can move through and condense on the walls as you have essentially coated the metal. There seem to be two schools of thought when using fiberglass in this situation- one is make sure you have a good vapor barrier on the warm side (inside the shop) of the fiberglass so moisture can't move through and get into the insulation. The flip side of that is that you can't ever have a completely sealed vapor barrier and some moisture will get in, thus some say not to put in a vapor barrier so that moisture that does get in can vaporize and move back and forth freely. In a house that uses fiberglass, the siding and housewrap allow any moisture that moves into the walls to move out through the house wrap and siding, but metal is not permeable in the same way. That being said, I insulated my shop with fiberglass batts and put up a 6 mil vapor barrier sealed with tape- inexpensive and effective and do not have moisture problems that I am aware of. If you can keep the insulation from touching the metal siding so much the better- any moisture that forms on the metal won't soak the insulation. The spray foam has some advantages of keeping wind out, no nesting for critters and reportedly stiffens up the whole building. You also have to think about your climate, high humidity worsens the moisture movement and I don't have that where I live.

 

[Dishpointer]

I live in the same area as you and I insulated our 40X 60 X 12 Shop with spray foam on all walls and 14" of blown in cellulose in the ceiling. The interior is finished off with white metal like the above picture. Although the cost of the foam was higher than the other options, it was the best option for me. It made the walls more rigid, it doesn't have the condensation problem that other insulation has because of contact with the exterior metal walls, and it seals all air gaps. I just installed a 100K btu propane furnace this week and it will heat the shop up from 45 deg to 60 deg within 10 minutes and the furnace won't kick back on for 30-40 minutes. And that's with an outside temp in the mid 20's!
If I were to do it all over again, I would definitely use spray foam again. It does cost more up front but the energy savings are worth it.

 

[raasd]

Our shop is insulated with fiberglass batt, but if we had to do it over again, spray foam all the way. we have in floor heat which is the way to go if you ask me. We can keep the shop about 10 degrees cooler and it still feels warm. You can lay on the floor and not get cold, and your feet don't get cold. It is efficient and effective. Our shop is 40X60.

 

[crbr]

Spray.

Much more advanced in efficencies gained. A superior product.

 

[monteu]

It seems that spray foam has the most votes! This will cost 6 to 7 times what the rollout fiberglass insulation, 5x more than polystyrene with foil back, and 2x more than RMax insulation board with foil back. I actually have a friend here that does spray foam for a living and I know he would do a good job. It is just that when I am getting a loan to build this shop is it wisdom to spend that much extra on insulation? It just might be.