Very thin insulation and flooring?

Hi,
I regularly remind people that they don't always want a drill bit, they want a hole. I'm going to try to frame my question in that spirit.

I have part of a shed walled off and insulated for a drying room. I need to keep this room a little warmer than it is for the most efficient drying. I have a dehumidifier that runs that can keep it around 70F when it is 30F outside. Not too bad... but I need a little bit better for the fastest drying. I need it above 80F, 90F is fine too.

The walls and ceilings are 2x4 construction and insulated between studs. The floor has no insulation, and it is too low, for me to get under to add insulation that way. I'm assuming my best options are to either get a tiny heater or add more insulation, or both.

I would not want the floor to come up more than 1.5 inches. I would want it to be natural (or reasonably natural materials, e.g. I'm ok using mineral wool insulation). I do need to be able to sweep the floor too.

I have a couple half ideas, but I don't want to sway thoughts if someone has a good idea completely different than I was thinking. Thoughts?

Is the shed foundation pier and beam? If so you could cut out the plywood subfloor to access the joist bays to put in mineral wool batts. It's not too tricky especially if the plywood was put down with screws.

Insulate the floor on top of the floor rather than under it.

Lay an ultra thin emergency blanket down first, you know that shiny mylar stuff?

Add new floor joist on top of the floor, then you lay insulating material on top and put down a new floor.

Following, as I'm interested to hear the replies.

I have a similar situation in a couple of rooms in my house.

Two have sawn floorboards, but I think just butted together not T&G. No access to under the floor. I doubt there's any subfloor, and I'd rather not take up the floorboards.  

There are two other rooms with flooring issues, too, but they have different challenges!

If the shed is on pier and beam blocking off the crawlspace to keep the wind out will help keep the space warmer.  

Aaron Yarbrough wrote:Is the shed foundation pier and beam? If so you could cut out the plywood subfloor to access the joist bays to put in mineral wool batts. It's not too tricky especially if the plywood was put down with screws.

Aaron Yarbrough wrote:If the shed is on pier and beam blocking off the crawlspace to keep the wind out will help keep the space warmer.

It is sitting on three beams which are sitting on piles of bricks to level it out. I'm ashamed to say I had not thought about blocking off the bottom yet. On one side it is mere inches to the ground, but the other side is probably 8 or 9 inches off the ground.

I had thought about cutting it out, adding insulation and then putting the floor back down... I am just having trouble with the fact that it is a new shed... and I hate to be that destructive. Though... that may be the best option long term.  

Anne Miller wrote:Insulate the floor on top of the floor rather than under it.

Lay an ultra thin emergency blanket down first, you know that shiny mylar stuff?

Add new floor joist on top of the floor, then you lay insulating material on top and put down a new floor.

I like this idea in general, and have used it before... but I do not have enough height in the room, to essentially add another floor.

So the two half ideas that I thought of were to use the 1" thick rockwool comfortboard 110. This should be dense enough to stand on... and then I could put a floating floor on top. My issue is I haven't been able to find 1/2 inch boards... and I'm trying to avoid plywood.

My other idea was to perhaps mix in a bunch of perlite or vermiculite into clay and put a thin earthen floor over it. My worry with this method is that if I put in enough perlite to help with insulation, I worry the clay would not hold together well enough. Also, since it is a drying room, I worry the clay would get too dry and crack.

Hey Matt.
How well insulated are the walls?
How about the roof?
What about the door, assuming there is one?

Usually you loose most heat through the roof, then walls, then windows and doors.

Could you get under the floor and insulate between the battens/beams? A couple of inches of insulation could do a lot.

I understand you don’t want to cut up your freshly built shed, so adding another layer to the existing floor sounds like a good idea to me.
Clay and perlite won’t help much as you say.

How about cork (or wood fiber, let’s say 1,5 “) and a thin layer of wood or laminate or whatever (.5” or less)?

Hmmm, I had not thought about cork. I'm going to have to go research that.

The walls and ceiling are insulated with R15 rockwool batts. Then covered in 3/4" pine boards. There is some space between the ceiling and the roof, a triangle space. I have only sealed the vents in the roof. Nothing more yet. There is an outside door leading to the front half of the shed... then a room with another outside door to the outside.

2 thoughts
- lift shed base to a practical height and insulate the floor well.
- use cool room panels which have sheet steel both sides on top of existing floor, they come 50mm thick.

Matt McSpadden wrote:

Anne Miller wrote:Insulate the floor on top of the floor rather than under it.

Add new floor joist on top of the floor, then you lay insulating material on top and put down a new floor.

I like this idea in general, and have used it before... but I do not have enough height in the room, to essentially add another floor.

Simple, would 2 inches make that much difference in height?  Use a 1 x 2 for the floor joist.  Two inches of some sort of insulation material is better than none.

Or use 1 x 1 as one inch insulation material is better than none.

The  ultra thin emergency blanket down first will have some value even if used alone.

Matt McSpadden wrote:I'm assuming my best options are to either get a tiny heater or add more insulation, or both.

We haven't addressed the tiny heater side yet ....

How often do you go in the drying room? Would taking in some sort of heat battery (like hot rocks, or liquid wax) be an option? What's your climate like in winter - sunny days for solar space heating perhaps (I'm wondering about trombe walls...)?
How warm is the room next door? You describe it as a shed, so I'm assuming less warm. Is the door to that insulated and sealed too? If warmer - can you steal some of the warmth from there somehow.

Anne Miller wrote:

Simple, would 2 inches make that much difference in height?  Use a 1 x 2 for the floor joist.  Two inches of some sort of insulation material is better than none.

Or use 1 x 1 as one inch insulation material is better than none.

The  ultra thin emergency blanket down first will have some value even if used alone.

You know... an extra half inch might not be too bad. I would have to re-measure. If I kept the insulation to 1", could use a 3/4 or 5/8 flooring over it. Hmmm....

Nancy Reading wrote:
We haven't addressed the tiny heater side yet ....

How often do you go in the drying room?

Probably not more than once during the drying cycle, because so far, the drying room is always far warmer than outside of it. So I don't want to drop the temp too much.

Nancy Reading wrote:Would taking in some sort of heat battery (like hot rocks, or liquid wax) be an option?

I think these would work a little on the shoulder season... maybe help even out the heat a little during the summer. But in the winter, I would need to get the heat from somewhere else first and then move them into the room.

Nancy Reading wrote:What's your climate like in winter - sunny days for solar space heating perhaps (I'm wondering about trombe walls...)?

See... this is why I ask questions. I can think of these things for other people, but as soon as its mine, I forget :)

I don't think I could put one directly in the drying room, because it would create too many extra holes for bugs to creep in... but I could build one for the room next door... which would slow the heat leaving the drying room next to it. Good idea.

Nancy Reading wrote:How warm is the room next door? You describe it as a shed, so I'm assuming less warm. Is the door to that insulated and sealed too? If warmer - can you steal some of the warmth from there somehow.

Unfortunately it is not very warm right now. The wall between the rooms is insulated. But the outside walls of the second room has not been insulated yet. I plan to... just had to finish electrical stuff first. It acts as a bit of an air lock for the drying room. You have to walk through it to get to the drying room. No heat to steal... but I can certainly finish insulating it, and that should help some.

Maybe surround the base of the shed with discount hay/straw bales -- everywhere but the door? You can do one rank deep or tall, or more if it seems worth it. This does invite rodents to live under there, but that might not matter.

If height is a big part of your equation, I  think John has your dilemma solved.  One inch insulated panels surrounded by metal....then critters and bugs can't colonize your insulation , and no need to install a floating floor
Depends on cost,  but his idea offers significant time savings

If you're not apposed to paint, there is an additive to paint that might help. back in the 80's when i was studying ceramic engineering some folks were experimenting with light weight thin insulation ideas and they came up with making tiny bubbles (microspheres) in clay dust particles, then putting it into paint. Do an internet search for ceramic microspheres paint additive. there are industrial applications of this tech being used to limit corrosion on high temp pipelines. HyTech and Super Therm are two that i remember using to cool a metal roof.

J. Syme wrote:If you're not apposed to paint, there is an additive to paint that might help. back in the 80's when i was studying ceramic engineering some folks were experimenting with light weight thin insulation ideas and they came up with making tiny bubbles (microspheres) in clay dust particles, then putting it into paint. Do an internet search for ceramic microspheres paint additive. there are industrial applications of this tech being used to limit corrosion on high temp pipelines. HyTech and Super Therm are two that i remember using to cool a metal roof.

I am trying to avoid any paint that would offgas, so this may not work for this situation... but that is a really cool technology that may work for other things.

Matt McSpadden wrote:

J. Syme wrote:If you're not apposed to paint, there is an additive to paint that might help. back in the 80's when i was studying ceramic engineering some folks were experimenting with light weight thin insulation ideas and they came up with making tiny bubbles (microspheres) in clay dust particles, then putting it into paint. Do an internet search for ceramic microspheres paint additive. there are industrial applications of this tech being used to limit corrosion on high temp pipelines. HyTech and Super Therm are two that i remember using to cool a metal roof.

I am trying to avoid any paint that would offgas, so this may not work for this situation... but that is a really cool technology that may work for other things.

yep agree it is paint... it's good at blocking Infrared heat from the sun, okay at blocking thermal transfer from other sources. keeps hot side hot and cool side cool. a lot of info on spicoatings website.

They make blow-in mineral wool insulation.

You can skirt the shed, then drill smallish holes in convenient places in the floor or the tallest skirt, and blow the whole crawl space full. I would only do this with mineral wool, any other insulation holds too much water and isn’t bug proof enough. Mice will still chew through mineral wool to nest, though, so you need to seal the skirt.

R Scott wrote:They make blow-in mineral wool insulation.

You can skirt the shed, then drill smallish holes in convenient places in the floor or the tallest skirt, and blow the whole crawl space full. I would only do this with mineral wool, any other insulation holds too much water and isn’t bug proof enough. Mice will still chew through mineral wool to nest, though, so you need to seal the skirt.

Now there is an idea I had not thought of. It wouldn't take too much since it is so low to the ground. Like you said, rodents can and will still nest in it... but it less pleasant of a thing to chew, and if I sealed the edges, it might not be too bad.

I had some rockwool insulation left over, and I used it to tuck in around the base of the shed this evening. We will see how it helps. The temp has gone up 1 degree so far, and typically at night it is going down. I'll keep you posted on how it does with just that. I will be finishing the inside insulation for the second room, which should help some.

I think I gained about 2 degrees overall. Nothing earth shattering, but a little better.

Would it be possible to create a radiant solar powered heated floor system that you could then lay another layer of plywood on?
Or make a solar powered heated mat, like for seed starting?

I was able to get most of the insulation done on the front room, and I think that might have gained me another degree or two.

Unfortunately, it is a shed, and it was just not build to be insulated really well. I ended up getting what is sometimes called a milkhouse heater. It took me a little while to get it set to the right temp... because it is just a dial with low and high... but it helps keep it at temperature over night. And that is what I needed.