Can almost see the starting line

[Dave Lessley]

A few months ago I posted a few questions around re-building my shop. The long story short I have a 24x30 pole building that is 30+ years old that I'm tearing down and replacing it with a stick built structure. The existing building has just enough problems with non pressure treated poles, aging siding, home made trusses, and leaky roof that I was not comfortable putting the money it would require into it and still have a compromised infrastructure.

So for the last couple of months I have been emptying the existing structure in preparation to tear it down and build the new one. I will have a before and after photo of the scope of that one piece of the project Monday. (just need to figure out how to post pictures)

Monday demolition starts and and I'm told 4-6 weeks for completion depending on how long it takes me to do my part (electrical).

As I'm not excited about standing on concrete when I'm out in the shop I'm considering putting in a wood floor over the top of the concrete. My current approach is to lay down plastic sheeting 2x4 sleepers laying flat anchored to the concrete on 16" centers with hard foam insulation between sleepers plastic sheeting over the top of that with 1 1/8 " tounge and groove plywood over the top of that.

I plan to use some of the 4x6 posts from the pole building as studs in part of one wall where I will be hanging my brackets for lumber storage.

The walls will be insulated to R21 and the ceiling R38. Walls will be 2x6 sheeted, vapor wrapped and sheeted with T 111 no groove with bats for a board and bat look on 16" centers to cover seams and nails

I'm using drywall initially for walls and 10' ceiling. Later I may put up some sort of wood paneling or ply 4' to 8' up from the floor. I want to see how bad I trash the drywall.

I will be placing outlets every four feet around the room on four different circuits alternating outlets in two different directions from the panel. they will be placed above 4' from the floor. 220 as needed for compressor, dust collection with 220 and 110 drops to machinery in the middle of the room.

Lighting will be three rows of 8 two tube T8 fixtures. Task lights as needed.

Windows will be high on the two long walls like a pole building. 8' wide x 9' high insulated roll up door.

Will be adding a bump out for a small bathroom with toilet and laundry style sink.

Okay with that said do I need to consider doing something different? Now is the time guys, if I need to be thinking about something I'm not.

Thanks for your input,

[Anthony Whitesell]

My question would be about the floor and the insulation. First, let's make sure I have the same picture. Concrete covered by plastic. Foam insulation on the plastic with 2x4 sleepers on top. The whole thing covered by T&G plywood which will be covered by tools, shelves, and benches:D. Do I have it right so far?

If I do, then I have two questions. Will the foam insulation cover the entire concrete slab or just under the sleepers?

Again if I have the layout correct, the foam insulation will be under the sleepers. How much weight will the insulation withstand before it crushes, collapses, and becomes worthless? I'd worry that the insulation may crush or crush unevenly and distort the floor.

You may want to rethink the insulation under the floor support sleepers and just place the insulation between the sleepers. Also take into account cold concrete, still air, and trapped moisture between the concrete and the plastic, which could lead to a mold or mildew problem.

[Dave Lessley]

Sorry if it was confusing. The foam is between the sleepers. The idea with the plastic is to keep the moisture away from the sleepers the foam and the decking. No plastic would lead me to think the mold and mildew would have direct access to the sleepers foam and the decking. But this is why I'm asking. What are your thoughts on how to avoid the mold and mildew?

[Glenn Clabo]

Look here...
http://www.sawmillcreek.org/showthread.php?t=25115

http://www.sawmillcreek.org/images/icons/icon4.gif How to Attach Images Inline
How to Attach Images Inline,
or, What You've All Been Waiting For (tm).

1. Start a New Post.

http://www.sawmillcreek.org/attachment.php?attachmentid=24662&d=1129090162

2. Click on the Paperclip (or Manage Attachments), and
upload your pictures as usual:

http://www.sawmillcreek.org/attachment.php?attachmentid=24663&d=1129090170

3. Now, click on the little Arrow next to the Paperclip. You will get a drop-down list of all images available for you to attach inline.

http://www.sawmillcreek.org/attachment.php?attachmentid=24664&thumb=1&d=1129090415 (http://www.sawmillcreek.org/attachment.php?attachmentid=24664&d=1129090415)

(It will insert an "ATTACH" tag, as follows.).

http://www.sawmillcreek.org/attachment.php?attachmentid=24666&d=1129091205

...and VOILA!

:D

__________________
_Aaron_
SawmillCreek Administrator

[Anthony Whitesell]

Honestly, I don't know. I have read all I have found on insulating concrete and it seems to be the perfect catch-22. A cool surface on one side, warm humid air on the other. Increase circulation to prevent mold/mildew, decrease air circulation to retain heat.

When I re-sheetrocked by basement, the pink insulation that was against the concrete was black (with mold/mildew I was told). I asked at a local hardware store, non-BORG but also non-expert. I was told to use the foam board insulation with a small airgap (~1/2") between the insulation and the concrete wall. I asked "What good is that? The cold air still gets in the basement." There was no answer. I put up sheet rock with no insulation behind it. My basement is not heated anyway, and I'd prefer not to chance a larger mold issue. Perhaps I should contact Owens-Corning customer service for their suggestions.

[Thom Sturgill]

Here's a link to a document (http://www.extension.iastate.edu/Publications/PM1562.pdf) (pdf) on insulating floors from Iowa State University. I would add that the foam should be caulked and sealed to the sleepers, the vapor barrier should also be taped at any joints.

[Dave Norris]

Are you pouring new concrete? If so, you may be able to put plastic under the concrete to act as a vapor barrier. Also, something to consider may be an epoxy coating to act as a vb too. Not all epoxy coatings are a vb, but some are. Then you don't have to worry about rips and tears.

Also, something to think about may be going to larger sleepers and then running dc pipes under the floor.

[Dave Lessley]

Caulking is a good idea. One of those things that does not cost a lot of money and I can do.

I will be building on an existing slab. I considered sub floor DC and electrical but decided it would be much easier to make changes with it over head. I'm not exicited about ceiling drops but to me it seems to be the lesser of two evils. If I had a crawl space it might be different.

[michael osadchuk]

.....the Iowa State paper is correct from my experience (and you can probably also find more exotic publications on insulation at www.cmhc.ca, the Canadian government housing agency)......

here is the sequence on an addition to my house with a basement 22x25 foot workshop built in 1982:

- undisturbed earth
- 5 to 6 " gravel with drainage tubing around the perimeter
- 2" solid foam slabs (sorry I don't have the grade information; they were white, much less expensive than 'unbubbled' blue foam sheets, and yes, graded for below grade, under concrete slab use)
- 6 mil vapour barrier; overlaps taped
- about 3.5 to 4" of poured concrete, with some 'chicken mesh' reinforcement laid on top of the plastic vb; poured in two sections

I didn't put anything (eg. wood flooring) over the concrete.

The concrete slab remains totally dry and warm in winter with only a 500 watt baseboard heater on (when needed).

Think about using a wall construction with 2 x 8 studs instead of 2 x 6; you will be able to put significantly more cheap pink insultation is the thicker stud cavities and reduce your heating costs, better maintain even temperatures; the stud spacing can be increased a bit, partially offsetting the greater cost of 2 x 8 studs.

michael
about 30 north of toronto, ontario, canada

[Jim O'Dell]

Only thing I'd recommend is to put your electrical 52" up from the floor. That way you can put a sheet of plywood length wise on the floor against the wall and not cover up the outlets. They should still be low enough that upper cabinets won't interfere with them, but might be close. Or run them sideways at 49" (measured to the bottom of the plate).
Not sure what the best plan for putting wood on concrete. Talk to someone that has done that type of installation. I'd think the floor could sweat and trap the water between the concrete and the plastic causing problems. Since the concrete is not new, it may not wick too much moisture up, but will some if there wasn't a moisture barrier put under it before it was poured.
Sounds like fun ahead!! Be sure to keep us up to date with pictures! Jim.

[Dave Lessley]

The floor is 30+ years old. I know there is no insulation (other than gravel) under the concrete. I had rubber cushioned mats in fromt of some of my workstations for several years.There was no moisture or any tell tale sign of where the mat was other than dirt when I pulled it up. The back side of the mats were clean and showed no signs of mold or mildew. I'm thinking with the 1 1/8 " decking and the foam sheets and the treated sleepers especially with the caulking or taping the heat from the shop should be fairly insulated from the concrete.

[John Keeton]

Couple of thoughts. I would not go to the expense and effort of constructing a new floor over the existing concrete. My thought would be to use some foam interlocking floormats in traffic and standing areas. They would give you a warm feeling, no condensation/moisture issues, some insulation, comfort to the old knees and feet, and a lot more money left for tools!!

You are in Washington, and I don't really know what your low temps are in the winter, but the gain from the 2x6 walls and extra batting may not be worth the cost or loss of space for a non-residential setting. Most heat loss occurs from air infiltration and rising heat through the ceiling. I would prefer spray in foam (R7 per inch) in 2x4 walls, with about 2.5 inches of foam in the ceiling, covered about 10" of cellulose. The extra money saved on the framing would probably cover the difference in the foam insulation, and you will have a much more comfortable arrangement.

On the light fixtures, go with low temp, high output. In my 24 x24 shop, I have seven 8' fixtures, osb walls painted white (but low light reflection) and no ceiling (spray foam on metal). The light is blinding! Everytime my young adult kids come in, they squint from the light. In a 24x30 building, I would think 24 light fixtures would be way overkill and uncomfortable.

Dave, you posted while I was composing this post. I see your mention of the mats - I still think it is the way to go.

[Matt Ocel]

Dave -

For your sleepers you can use mold restistant lumber. Although It may not be readily available in all markets. Its being used in a somewhat limited manor in my area. FYI Its painted blue.
Or you can have it sprayed to prevent mold.
But I think what you have propsed will be adequite.

[Dave Lessley]

John,

I have not purchased the materials for the floor yet so I still have time to consider these points. Currently I have used two rubber mats stacked and my back still aches after a couple of hours which is why I was considering the wood floor. Maybe it's the contrast of sitting all day in my job and standing up for that length of time regardless of the floor type.

Tempartures are moderate seldom do we see freezing for any length of time. The quote for spray foam insulation for my shop was $2500.00. Way more than the cost of the pink stuff. And that was just for the walls. I will be sheeting it. Using a vapor barrier and sheeting it again with off sets on the seams and taping the underlying seems. The top seems will have bats over them. I realize this is not the same as spray foam but I also come from the school of thought that a building needs to breathe a little.

I have considered high output lights. We use them at my work in our manufacturing area. They are a little too bright for me. I will be putting my lights on multiple switches so I can turn lights on over a specific area if that is where I will be spending most of my time for that session.

I have yet to talk to the lighting rep for our company. The 24 fixtures was what the web sites say to use with T8's for a 24x30 with a 10 foot ceiling. I will double check that information.

Matt,

The sheeting for my walls is painted blue so I now know why. If I do the wood floor it makes good sense to use the painted treated wood as well

[Dave Lessley]

Thanks for the observations and suggestions so far. When I respond and explain what I'm doing please don't take it as I'm not valuing your input. I'm only explaining how I got to where I am. Please by all means feel free to express your insignts. I appreciate it very much.

I do not have internet at home and will be leaving work today early to go work on clearing out some of the remaining clutter as I will be losing work time tonight and tomorrow celebrating my anniversary with my wife.

So if you respond and I don't it will be Monday before I will be able to read your comments.

Thank you all,

[John Keeton]

Dave, given that high of a quote for foam, I probably would not do that either, but I still would not go the extra for 2x6 walls. I just don't believe it would pay out, but you may want to have your local power company do an energy audit on your plans. The service is usually free, and pretty helpful. They may tell you that in your area the heavier wall insulation would be a better investment, but I doubt it. I guess you have to also consider the amount of time you will be in the shop, and whether you will heat it 24/7.

On the floor, it would seem that a floor system installed over sleepers anchored to concrete would not have the same cushioning effect as a suspended, or joisted, floor. Perhaps others would have a more experienced thought on that as I have never done that.

In followup on the lights, what we are really talking lumens, or total amount of visible light. If you can get the necessary "volume" of light with fewer, more spaced out, fixtures, with less wattage consumption, then you save money in the front end, and over time.

I hope you have a great weekend with the wife and end up taking her somewhere than to look at shop stuff!!