On the vapor crap, this will be as much a function of your location, weather, and heat/cool tendencies in the space as anything - in any case, having more than one vapor barrier is NEVER a good idea.
If you seal the slab first, then there should be no other vapor barrier involved, but putting masonry products against wood without some sort of protection for the wood will also cause problems, especially with brick being very fond of moisture -
For this application, one thing that could solve all the problems might be to lay 30# building felt (asphalt impregnated paper for under shingles) on TOP of the subfloor material, just under the bricks - don't overlap, just butt from strip to strip, and don't SEAL the gaps. Lay the brick sections over the building paper and mortar as you planned.
What this should accomplish is to make your original slab's seal coat the vapor barrier, and allow all moisture in the brick and under the inner subfloor to normalize into the room, which would have humidity control. Setting the dehumidifier's control so it maintains 40% RH within the conditioned space, and the circulation fans we discussed on the phone, would keep the entire space within the OUTER walls at a constant humidity level that is low enough NOT to cause problems with mold growth, etc -
Any time you put wood against masonry, you run the risk of the wood absorbing moisture from the masonry - so if it's not bad in another way, I would advise using PT in these cases.
Alternatively, you might (under your floor for example) instead separate any wood framing from concrete using a double layer of 30# building felt, same stuff as under your bricks; and no, don't use the double layer under the bricks, too much chance of blocking one of the seams so moisture can't travel.
Doors - if you can spare the space, yes. Use a wider gap, use absorbent within the "vestibule" created - the absorbent helps kill some of the leakage from seals, improving isolation a bit; and the wider gap will help the doors "keep up" with the rest of the structure isolation-wise.
Try NOT, however, to make this "vestibule" SQUARE (as in having equal dimensions) - and don't end up with triple leaf construction by leaving the inner wall construction extended into the vestibule; exception to this might be if you intend to be making noise while people are using the door... Steve
FINISHED IN 2020! Sharward's Partial Garage Conversion
Moderators: Aaronw, John Sayers
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sharward
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Roofing Felt, Eh?
I dig it!knightfly wrote:. . . lay 30# building felt (asphalt impregnated paper for under shingles) on TOP of the subfloor material, just under the bricks - don't overlap, just butt from strip to strip, and don't SEAL the gaps. Lay the brick sections over the building paper and mortar as you planned.
What this should accomplish is to make your original slab's seal coat the vapor barrier, and allow all moisture in the brick and under the inner subfloor to normalize into the room, which would have humidity control. Setting the dehumidifier's control so it maintains 40% RH within the conditioned space, and the circulation fans we discussed on the phone, would keep the entire space within the OUTER walls at a constant humidity level that is low enough NOT to cause problems with mold growth, etc -
That seems like it would work very nicely! I just hope it's "kosher" for inspector's sake.
I got to thinking about the "circulation fans" thing... I'm assuming you're referring to some kind of thin ductwork (I had proposed fashioning something like this drain pipe -- the one with the holes) around the perimeter between the wall frames. However, I've since had second thoughts about this approach -- if I am pushing air through this area to ventillate it, wouldn't that reduce the effectiveness of the rather thick insulation throughout the area in terms of fireblock protection? (Recall that I'm anticipating needing to have a bulletproof explanation for the building department why I'm not using "conventional" fireblocks, for iso purposes, and that the insulation hopefully will suffice.)
Any time you put wood against masonry, you run the risk of the wood absorbing moisture from the masonry - so if it's not bad in another way, I would advise using PT in these cases. . .
Bear in mind that I had already planned to use two layers of redwood 2x4s to frame the perimeter of the floor, on the room side of the joists -- which is naturally rot-resistant, and also more attractive (and safer for indoor use, I presume) than PT. Do you think that will be OK?
Alternatively, you might (under your floor for example) instead separate any wood framing from concrete using a double layer of 30# building felt, same stuff as under your bricks; and no, don't use the double layer under the bricks, too much chance of blocking one of the seams so moisture can't travel.
By "alternatively" I assume you mean "instead of sealing the concrete slab (garage) floor" -- correct? With the exception of the soleplates of the north and northwest outer leaf walls I'll be building, there will be no direct contact between slab and wood -- there will be the EPDM pucks as "feet" on all of the floating floor structure's vertical "legs." (I believe this differs from a lot of folks' basement projects, where they don't need to level the floating floor framing structure.) Is that sufficient separation? If not, perhaps a couple of 8" square pieces of asphalt impregnated paper would be good between the pucks and the concrete...? And the legs themselves should probably be made of PT 2x4s, as illustrated in my latest drawings -- right?I really appreciate everyone's assistance in getting this issue dialed in... It's fundamentally important!
(And it's
cool that this thread is now officially 
! 
Hee hee...)-
knightfly
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if I am pushing air through this area to ventillate it, wouldn't that reduce the effectiveness of the rather thick insulation throughout the area in terms of fireblock protection? (Recall that I'm anticipating needing to have a bulletproof explanation for the building department why I'm not using "conventional" fireblocks, for iso purposes, and that the insulation hopefully will suffice.
Things like this are almost always better left until AFTER the permits are finalized/signed off and the inspector has taken his bureaucratic bull elsewhere to hassle some OTHER poor defenseless taxpayer...
I would find out about/do the rigid fiberglass fireblock deal, keeping a way to add the air cicrulation scheme LATER - if you were to ever have a fire, the low flow of air wouldn't make much difference anyway; and before too long any wires feeding the fan would short out and the fan would stop altogether anyway.
Bear in mind that I had already planned to use two layers of redwood 2x4s to frame the perimeter of the floor, on the room side of the joists -- which is naturally rot-resistant, and also more attractive (and safer for indoor use, I presume) than PT. Do you think that will be OK?
Naturally rot resistant, maybe a LITTLE - but not nearly as much as it's given credit for. That reputation was earned a century ago when men cut down a huge redwood, threw away all but the HEART, and made that part into things that wouldn't rot. That's the part of the Sequoia that's actually pretty rot resistant, for the same reason Cedar is; it has a higher concentration of SAP whicn, for the more aromatic woods, is very OILY and acts as a natural preservative. The stuff you buy these days is barely beneath the cambium layer of a tree, and is about as rot resistant as pine or fir, maybe a bit more.
More attractive - granted. But keep in mind that every brick you replace with wood (if that's your plan for those diamond shapes) is that much LESS MASS for your floor - might be better if you want a pattern of some sort to use different colored masonry for the diamonds instead.
By "alternatively" I assume you mean "instead of sealing the concrete slab (garage) floor" -- correct?
No, I meant instead of using redwood - use either PT (the non-deadly kind) OR at least put a couple layers of 30# felt between the concrete (still sealed) and any wood parts.
As long as the EPDM or other elastomer is what's in contact with the concrete, and as long as the concrete is smooth (whether level or not) then contact cement is all you'll need - in that application the building felt is unnecessary.
And the legs themselves should probably be made of PT 2x4s, as illustrated in my latest drawings -- right?
Right... Steve
Things like this are almost always better left until AFTER the permits are finalized/signed off and the inspector has taken his bureaucratic bull elsewhere to hassle some OTHER poor defenseless taxpayer...
I would find out about/do the rigid fiberglass fireblock deal, keeping a way to add the air cicrulation scheme LATER - if you were to ever have a fire, the low flow of air wouldn't make much difference anyway; and before too long any wires feeding the fan would short out and the fan would stop altogether anyway.
Bear in mind that I had already planned to use two layers of redwood 2x4s to frame the perimeter of the floor, on the room side of the joists -- which is naturally rot-resistant, and also more attractive (and safer for indoor use, I presume) than PT. Do you think that will be OK?
Naturally rot resistant, maybe a LITTLE - but not nearly as much as it's given credit for. That reputation was earned a century ago when men cut down a huge redwood, threw away all but the HEART, and made that part into things that wouldn't rot. That's the part of the Sequoia that's actually pretty rot resistant, for the same reason Cedar is; it has a higher concentration of SAP whicn, for the more aromatic woods, is very OILY and acts as a natural preservative. The stuff you buy these days is barely beneath the cambium layer of a tree, and is about as rot resistant as pine or fir, maybe a bit more.
More attractive - granted. But keep in mind that every brick you replace with wood (if that's your plan for those diamond shapes) is that much LESS MASS for your floor - might be better if you want a pattern of some sort to use different colored masonry for the diamonds instead.
By "alternatively" I assume you mean "instead of sealing the concrete slab (garage) floor" -- correct?
No, I meant instead of using redwood - use either PT (the non-deadly kind) OR at least put a couple layers of 30# felt between the concrete (still sealed) and any wood parts.
As long as the EPDM or other elastomer is what's in contact with the concrete, and as long as the concrete is smooth (whether level or not) then contact cement is all you'll need - in that application the building felt is unnecessary.
And the legs themselves should probably be made of PT 2x4s, as illustrated in my latest drawings -- right?
Right... Steve
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sharward
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Latest Drawings (or "Drawrings" if you're an SNL f
Well, I've been busy refining my illustrations over the last several days. Here they are. Sorry they're so dang tall, but at least they're not wide and causing you to have to scroll sideways.
All feedback is welcome!
All feedback is welcome!
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sharward
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One more illustration...
Last one (for now)...
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knightfly
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Looking really good Kieth; only one change I'd make so far, that's to move part "F" back so it overlaps the top plates by 2 to 2-1/4", this will still leave enough fastener support for 3 layers of wallboard, and in addition it will make the support plate more stable; with that much overlap, you can toenail that 2x6 tightly so it won't "rock" with the added weight of the gypsum.
Also, the orientation for your bricks is normally called "edge-laid" IIRC.
Any test results back on the EPDM yet? Steve
Also, the orientation for your bricks is normally called "edge-laid" IIRC.
Any test results back on the EPDM yet? Steve
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sharward
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Actually, my spec is 1 1/2" from outer edge -- meaning, away from the inside of the room. That means it will be flush against the rim joist of the ceiling joists along the east and west walls, whereas it leaves 1 1/2" uncovered along the short north and south walls. I think you read that as having only 1 1/2" of coverage along the top plate. My plan allows for 2 full inches of coverage with 3 1/2" hanging over to attach the three interwoven layers of gypsum.knightfly wrote:. . . move part "F" back so it overlaps the top plates by 2 to 2-1/4", this will still leave enough fastener support for 3 layers of wallboard. . .
The drawing is to scale, (with the obvious slice through the middle) so you can get a good idea of how sturdy that will be.
Great idea.. . . you can toenail that 2x6 tightly . . .
Unfortunately, the EPDM sample Rubber-Cal sent me was 1/8" thick, not 1/2" thick as I had requested.Any test results back on the EPDM yet?
It's also only about 2" x 3", so layering it isn't even an option. Apparently I'll need to get them on the phone to ask for a more generous sample of the correct thickness... If they balk, I'll offer to "purchase" the sample if they apply the amount towards my upcoming $500 order.Nice rubber though. This looks like a real winner and I'm extremely glad you turned me onto it.
I'm continuing to work madness on my "spreadsheet from hell," which is how I'm accounting all the estimated weight and costs of materials. I have a healthy respect for the fact that those efforts will make or break this project, and I'm looking forward to handing in that assignment to Professor Knightfly, hopefully next week.
...But...But...it smells...soooo...gooooood...I...I don't...I can't.........resist.......Rubber-Cal, in the letter that accompanied the EPDM sample, actually wrote:P.S.: Most elastomers are poisonous and hazardous to the digestive tract so please, please, please do not attempt to eat it.
...Chomp...
... ... ... ............... 
............... ... ... 
... ... 
...Thud...
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sharward
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I bought my EPDM today!
I'm very pleased to report that I purchased an "overrun" of 1/2" thick 60 durometer EPDM today from a company called BRP -- a 2' x 3' sheet that will allow me to cut out about 164 individual 1 1/2" x 3 1/2" pucks. I was very pleased with the price (about US$70 plus ground shippping, billed to credit card) and especially happy that I didn't have to meet a minimum, since it was essentially a left-over piece. You can check out their "hopefully current" inventory of overrun stock - type "60D EPDM" in the "Part Number or Description" field to see what's available in 60 durometer EPDM. If you see something you like, you have to actually call them to make your purchase.
I made a very preliminary puck placement layout (below) that calls for 157 pucks. The spacing varies from about 10" to 20" apart, including diagonal, with closer spacing around the perimeter (walls).
I'm hoping that based on my final weight calculations that I'll revise the puck layout by actually removing legs/pucks rather than adding them. The most important thing I've learned here is that overloading pucks is almost as bad as underloading pucks, so it all comes down to accurate weights and measures. I'm accounting for this on a wild spreadsheet, and I'll post it when I'm done so that everyone has the benefit of my methods, and so I can blame y'all if something goes wrong.
And now, questions for Professor Knightfly...
So that I'm clear, we are looking for, ideally, 10% deflection, not 10% of the total deflectability (I just made up that word - do you like it?)... Right? I had initially misunderstood that. In other words, the material cannot deflect 100% because that would mean it would disappear; the maximum deflection is, I assume, somewhere around 40%-60%. Thus, it's the amount it compresses as a ratio of its total thickness, NOT a ratio of it's total compression span. Is that right?
Assuming that's the case, then I'm thinking that I won't need the super high tech testing method that we discussed privately after all. I could probably just get two pucks on a flat surface, place a stiff board across them, and insert a wafer that is 90% of 1/2" (i.e., 9/20" -- I'm thinking of a piece of 7/16" plastic or acrylic, with maybe a couple of sheets of paper added to it), shining a light behind it, then stacking weights on the board until the light disappears (touchdown on the wafer)... Then dividing the weights plus the board weight in half to determine the final ideal weight "per puck." Makes sense?
How much testing weight should I plan to need to put on it? (I'll likely need to borrow the weights from someone.)
Or would you rather see me do the high tech test, since I saved so much dough on the rubber?
I made a very preliminary puck placement layout (below) that calls for 157 pucks. The spacing varies from about 10" to 20" apart, including diagonal, with closer spacing around the perimeter (walls).
I'm hoping that based on my final weight calculations that I'll revise the puck layout by actually removing legs/pucks rather than adding them. The most important thing I've learned here is that overloading pucks is almost as bad as underloading pucks, so it all comes down to accurate weights and measures. I'm accounting for this on a wild spreadsheet, and I'll post it when I'm done so that everyone has the benefit of my methods, and so I can blame y'all if something goes wrong.
And now, questions for Professor Knightfly...
So that I'm clear, we are looking for, ideally, 10% deflection, not 10% of the total deflectability (I just made up that word - do you like it?)... Right? I had initially misunderstood that. In other words, the material cannot deflect 100% because that would mean it would disappear; the maximum deflection is, I assume, somewhere around 40%-60%. Thus, it's the amount it compresses as a ratio of its total thickness, NOT a ratio of it's total compression span. Is that right?Assuming that's the case, then I'm thinking that I won't need the super high tech testing method that we discussed privately after all. I could probably just get two pucks on a flat surface, place a stiff board across them, and insert a wafer that is 90% of 1/2" (i.e., 9/20" -- I'm thinking of a piece of 7/16" plastic or acrylic, with maybe a couple of sheets of paper added to it), shining a light behind it, then stacking weights on the board until the light disappears (touchdown on the wafer)... Then dividing the weights plus the board weight in half to determine the final ideal weight "per puck." Makes sense?
How much testing weight should I plan to need to put on it? (I'll likely need to borrow the weights from someone.)
Or would you rather see me do the high tech test, since I saved so much dough on the rubber?
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knightfly
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Gotcha...
OK, all seriousness aside;
First question, yes
Second question, right
Third question, see previous post...
OK, REALLY all seriousness aside...
This part (question 3) can get tricky to "second guess", partly because I'm not sure just how constant different manufacturer's Durometer ratings are, plus other variables like the amount of material left to "squish out" of the compression area, whether pucks will be ACROSS the joist or lengthwise, which would affect total surface contact area -
If I had to take a "SWAG", I'd say somewhere between 10 and 40 psi; so, if your contact area is 1.5" x 1.5", you'd be looking at around 20-80 pounds -
However, for this particular question I REALLY meant the PREVIOUS post... Steve
OK, all seriousness aside;
First question, yes
Second question, right
Third question, see previous post...
OK, REALLY all seriousness aside...
This part (question 3) can get tricky to "second guess", partly because I'm not sure just how constant different manufacturer's Durometer ratings are, plus other variables like the amount of material left to "squish out" of the compression area, whether pucks will be ACROSS the joist or lengthwise, which would affect total surface contact area -
If I had to take a "SWAG", I'd say somewhere between 10 and 40 psi; so, if your contact area is 1.5" x 1.5", you'd be looking at around 20-80 pounds -
However, for this particular question I REALLY meant the PREVIOUS post... Steve
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sharward
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OK. Well, I'm planning on going with 1 1/2" x 3 1/2" pucks, so that would be 5.25 square inches. Based on that swag, that's around 50-210 pounds. Doubling that is 100-420 pounds. That's a lot of testing weight. Perhaps I will go ahead and do the "high tech test."knightfly wrote:. . .If I had to take a "SWAG", I'd say somewhere between 10 and 40 psi; so, if your contact area is 1.5" x 1.5", you'd be looking at around 20-80 pounds . . .
The "hich tech test," by the way, is something that I hope a local machine/fabrication shop can do for me. They have special equipment that they can supposedly set up to test how many pounds of pressure these pucks can take at various compression rates. Hopefully I'll have the rubber soon so that I can get the testing done. It will cost me some money, but I'm hoping it will a lot of the guesswork out of the equation.
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sharward
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Finding 5/8" Gypsum That ISN'T Fire Rated
Steve, you've mentioned in several places on the forum that we should not use fire-rated gypsum if we can avoid it, since fire rated gypsum has less mass. However, I'm having a little trouble locating a supplier of NON-fire rated 5/8" gypsum.
Home Depot only carries 1/2" non-fire and 5/8" fire (besides 3/8", greenboard, etc.). Acoustical Material Services (a.k.a. "AMS") carries many types of gypsum, but they said "all 5/8" sheet rock is fire rated." They carry Gold Bond gypsum, and according to the National Gypsum Web site, that appears to be true.
Does this mean I should keep looking, and specifically look for a brand of gypsum wall board that comes in 5/8" and is NOT fire rated?
Also, there are many varieties of gypsum available... The above link demonstrates how many varieties are available. Should I be interested in any of these other types?
Finally (yeah, right), I got to thinking... rather than using PT 2x4 to to brace my PT 2x4 leveling block legs (as represented in my illustration, note "O"), should I use hot-dip galvanized metal fasteners instead? Do you think that would be more or less expensive? Easier or more difficult (given that I'll probably have over a hundred legs)?
Home Depot only carries 1/2" non-fire and 5/8" fire (besides 3/8", greenboard, etc.). Acoustical Material Services (a.k.a. "AMS") carries many types of gypsum, but they said "all 5/8" sheet rock is fire rated." They carry Gold Bond gypsum, and according to the National Gypsum Web site, that appears to be true.
Does this mean I should keep looking, and specifically look for a brand of gypsum wall board that comes in 5/8" and is NOT fire rated? Also, there are many varieties of gypsum available... The above link demonstrates how many varieties are available. Should I be interested in any of these other types? Finally (yeah, right), I got to thinking... rather than using PT 2x4 to to brace my PT 2x4 leveling block legs (as represented in my illustration, note "O"), should I use hot-dip galvanized metal fasteners instead? Do you think that would be more or less expensive? Easier or more difficult (given that I'll probably have over a hundred legs)?-
sharward
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Spreadsheet from Hell
Well, after several weeks of research, I'm finally ready to unveil my cost and weight estimate spreadsheet. I'm very interested in feedback on this, especially from Steve (of course ).
I'm utterly amazed at how much my structure is going to weigh -- floating floor, walls, and ceiling (the "box within my box") is going to weigh about 15,000 POUNDS (7 1/2 TONS) or about the weight of six small cars! I'm a little bit freaking out about this, wondering if my garage floor will handle it in such a relatively small area. I'm also concerned that I'll have to buy more EPDM material for pucks, as I'll only have enough for about 90 pounds per puck, assuming I distribute the pucks properly.
Needless to say, I'm most interested in feedback about my weight estimates. If I screw this up, I'm toast.
Many thanks to all.
).I'm
utterly amazed at how much my structure is going to weigh -- floating floor, walls, and ceiling (the "box within my box") is going to weigh about 15,000 POUNDS (7 1/2 TONS) or about the weight of six small cars! I'm a little bit freaking out about this, wondering if my garage floor will handle it in such a relatively small area. I'm also concerned that I'll have to buy more EPDM material for pucks, as I'll only have enough for about 90 pounds per puck, assuming I distribute the pucks properly.Needless to say, I'm most interested in feedback about my weight estimates. If I screw this up, I'm toast.
Many thanks to all.
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knightfly
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Kieth, just a quick try before I crash;
Does this mean I should keep looking, and specifically look for a brand of gypsum wall board that comes in 5/8" and is NOT fire rated?
I hope you misinterpreted a statement from me, and I didn't use the term Fire Rated when describing separate sheets of drywall; The term for a specific formulation of drywall wouldbe Fire CODE, or "X-Core" - this refers to non-gypsum additives that raise the temperature at which the gypsum cracks, etc, letting air/smoke through.
Fire RATED assemblies can use STANDARD formulations of gypsum, it's more the thickness/layers vs type of framing that determines whether a wall is a 1-hour fire rated wall, or a 2-hour fire-rated wall; there are specific temperatures, etc, that are spec'd for these ratings.
So, any gypsum wallboard can be "fire RATED", when used in a proper wall ASSEMBLY: but only specially FORMULATED gypsum can be "X-Core", or Fire CODE, gypsum. This type of gypsum is the one with a slightly less dense makeup, due to the different composition of the board itself.
Also, there are many varieties of gypsum available... The above link demonstrates how many varieties are available. Should I be interested in any of these other types?
No - see above.
Finally (yeah, right), I got to thinking... rather than using PT 2x4 to to brace my PT 2x4 leveling block legs (as represented in my illustration, note "O"), should I use hot-dip galvanized metal fasteners instead? Do you think that would be more or less expensive? Easier or more difficult (given that I'll probably have over a hundred legs)?
Hard to say on that one; you want to maintain stiffness, so will likely want some blocking BELOW your 2x6 joists where the "legs" are tallest; otherwise, you may get more sway in the floor than you want.
Costwise; things are just plain crazy, you'd need to cost out the brackets and compare to PT lumber prices. I bought a single 20' length of 4x4 square steel tubing last week, 3/16" wall thickness - 2 years ago that would have cost about $60, last week it was $179 - 1" EMT last week at HD was $10 per stick, over 3 times what it cost a couple of years ago. The PVC conduit was still around $3.
At those prices, you might be ahead to use CONCRETE spacers... Steve
Does this mean I should keep looking, and specifically look for a brand of gypsum wall board that comes in 5/8" and is NOT fire rated?
I hope you misinterpreted a statement from me, and I didn't use the term Fire Rated when describing separate sheets of drywall; The term for a specific formulation of drywall wouldbe Fire CODE, or "X-Core" - this refers to non-gypsum additives that raise the temperature at which the gypsum cracks, etc, letting air/smoke through.
Fire RATED assemblies can use STANDARD formulations of gypsum, it's more the thickness/layers vs type of framing that determines whether a wall is a 1-hour fire rated wall, or a 2-hour fire-rated wall; there are specific temperatures, etc, that are spec'd for these ratings.
So, any gypsum wallboard can be "fire RATED", when used in a proper wall ASSEMBLY: but only specially FORMULATED gypsum can be "X-Core", or Fire CODE, gypsum. This type of gypsum is the one with a slightly less dense makeup, due to the different composition of the board itself.
Also, there are many varieties of gypsum available... The above link demonstrates how many varieties are available. Should I be interested in any of these other types?
No - see above.
Finally (yeah, right), I got to thinking... rather than using PT 2x4 to to brace my PT 2x4 leveling block legs (as represented in my illustration, note "O"), should I use hot-dip galvanized metal fasteners instead? Do you think that would be more or less expensive? Easier or more difficult (given that I'll probably have over a hundred legs)?
Hard to say on that one; you want to maintain stiffness, so will likely want some blocking BELOW your 2x6 joists where the "legs" are tallest; otherwise, you may get more sway in the floor than you want.
Costwise; things are just plain crazy, you'd need to cost out the brackets and compare to PT lumber prices. I bought a single 20' length of 4x4 square steel tubing last week, 3/16" wall thickness - 2 years ago that would have cost about $60, last week it was $179 - 1" EMT last week at HD was $10 per stick, over 3 times what it cost a couple of years ago. The PVC conduit was still around $3.
At those prices, you might be ahead to use CONCRETE spacers... Steve