Question re insulating the floor in my workshop

[Rob Russell]

Rob ... I hope that you are not just doing the symbols for me and that you will be able to use them elsewhere.

This is not solely for the DC schematics. I need to do an electronic version of the schematic for my phase convertor and will use the symbols from the DC when I do that diagram (plus more - you don't need capacitors, a phase monitor, potential relay etc. for the DC contactor).

[Frank Pellow]

Well, I found some galvanized wire mesh with a 1/4 inch opening.

The good news is that it certainly looks like rodents could not get through it.

The bad news is that it is really expensive (a little over 70 cents US a square foot, including taxes).

I am now considering using only the mesh (not wood of any kind), stapling the mesh to the underside of the joists, and inserting the insulation at the top of the joists where I am told by the manufacturer it will stay. The quote from a Roxul rep is "the product is designed for friction fits and therefore you likely wouldn't need any strapping". Since the insulation is 5.5 inches thick and the joists are 7.5 inches thick, this will leave two inches between the mesh and the insulation; making it even harder for critters to get at.

[Chris Padilla]

Do what you can to keep the critters from getting under your shop to begin with and you'll have a shot. Critters are remarkably resourceful and the underside of your shop will be quite inviting and tempting...they will tax themselves striving for that beach-front property!

[Frank Pellow]

Chris, I plan to install rigid wire fencing at least 6" into the ground around the perimeter of the building and extending up above the ground by about a foot to meet the siding. I will then cover that with lattice stained the same colour as the siding.

The only thing that I am still in doubt about is whether to put the vapour barrier below or above the sub-floor.

[Robert Ducharme]

The vapor barriers main purpose is to isolate materials that should not have humidity from the interior living spaces which have humidity (showers, breathing, etc).

assuming you have

• flooring
• sub-flooring
• insulation

I would place the vapor barrier below the sub-flooring and above the insulation. I do not think you will have enough moisture to really bother sub-flooring especially if you do the flooring okay. Also, if the floors are pretty water proof (painted, etc), I am not even certain why you are putting any in at all. I can see it more if you have drywall.

[Frank Pellow]

Today I installed the first section of insulated sub-floor. I am attaching some photos that illustrate the structure that I decided upon. I thank all of you who contributed to me deciding upon this method.

The insulation is mineral wool (40% recycled) rather than fiberglass. A local guy that I talked to told me that he used it in his crawl space and that raccoons hate it.

I also included a photo of the tool I am using to screw the strapping under the joists. I sure could use a Festool CD 12 FX drill with a right angle chuck, but I don't have one, so the improvised tool will have to do. Actually, it is surprisingly fast.

[Jim Becker]

Lookin' good, Frank. The mineral wool is a pretty good solution...I had forgot about it since it doesn't get used that often, especially in residential work around here. Do wear gloves, long sleaves, eye protection and take a cold shower after working with it, however! (Same actually applies to fiberglass, too...)

[John Miliunas]

I also included a photo of the tool I am using to screw the strapping under the joists. I sure could use a Festool CD 12 FX drill with a right angle chuck, but I don't have one, so the improvised tool will have to do.

Sheeeesh Frank! I feel the pain of having to screw the strapping up in that fashion way down here! The Festool would be the hot tip! But, I think I've seen right angle attachments for regular drill somewhere. Don't thing they were that expensive, either. Even a cheap one would have to do better than what you've got going there. You're going to end up with Carpal Tunnel doing too much of that! Ouch!!! I'll grant you this: You shore do have a lot of moxie! Like I said on the other thread, I'd still probably be staring at the painted circles about now! Kudo's, my friend! You deserve it!

[Ed Weiser]

Frank--
Great job!! I realize it must be a real pain to get under that floor system to attach the mesh but I think in the long run you'll be quite pleased. It looks like you've got 8+ inches of mineral wool insulation. What kind of R-value will that give you? Looking forward to the next group of photos!!

Ed

[Frank Pellow]

If I can find a right angle attachment that fits my electric drill (a cheap Ryobi), I would cetainly be interested. I briefly looked into such a thing about a year ago and was not successful.

I am going to Home Depot tomorrow morning early to pick up more insulation and will check to see if they have such an attachment.

[Frank Pellow]

Frank--
Great job!! I realize it must be a real pain to get under that floor system to attach the mesh but I think in the long run you'll be quite pleased. It looks like you've got 8+ inches of mineral wool insulation. What kind of R-value will that give you? Looking forward to the next group of photos!!

Ed

The insulation in 5.5 inches think. The R value is R21.5.

[Chris Padilla]

Frank,

Look for a flexible cable for your drill as well...it might work for you. I have the right angle attachment for my Festool CDD12 drill...pretty nice however the eccentric drive is bloody awesome!

[Frank Pellow]

Lookin' good, Frank. The mineral wool is a pretty good solution...I had forgot about it since it doesn't get used that often, especially in residential work around here. Do wear gloves, long sleaves, eye protection and take a cold shower after working with it, however! (Same actually applies to fiberglass, too...)

Thanks for the advise Jim. I did wear gloves and long sleaves today and am off shortly to take a shower.

[Frank Pellow]

Frank,

Look for a flexible cable for your drill as well...it might work for you. I have the right angle attachment for my Festool CDD12 drill...pretty nice however the eccentric drive is bloody awesome!

Flexible cable, that sounds NEAT. I never knew that there was such a thing.

[Jim Becker]

Thanks for the advise Jim. I did wear gloves and long sleaves today and am off shortly to take a shower.

Cool water is best in this case as it will not open your pores to any fibers that happen to "be there". Once you are completely rinsed, you can kick up the heat to normal! I worked for a couple of years for an insulation contracting company owned by a former father-in-law and learned that one really quick!