yet another basement

[musicman74]

Hello all,
It's been awhile since I posted but I've been busy in between my day job stripping the room down to the block walls. I found some water damage behind the paneling(which was disposed of )Currently I have patched all the cracks in the mortar joints and sealed w/ dryloc on the interior walls. I also discovered a crack on the exterior foundation wall and am in the process of digging out and repairing it and taking care of drainage issues.I should also add that I tore out the built in closets due to the damage. Damn setbacks!We've had quite a bit of rain here lately and the basement is dry, even with the exterior crack still not fixed. Before I sealed the interior wall the block was damp where the crack is on the outside.Once that is repaired I shouldn't have any water issues but never say never right?

So I have a few new questions to pester you with
1: There is about a 1/8"gap where the wall meets the slab, should I use some type of sealant here or will I increase the possibility of flanking if I seal it w/concrete patch? I'm sure there are some points where there is hard contact.

2:Walls...Steve had recommended gluing the drywall directly to the block but in light of the water damage I'm reluctant to do this. Considering that the back wall is below ground exept for the top 2' would framing out a wall 1" off the block affect things considerably?I know it would be a 3 leaf wall but I would like for air to circulate to prevent mold and have insulation to keep things cozy. I would probably glue the dry wall direct on the other walls. My other thought is to not build any walls and treat the block wall with absorbers to tame the reflections.

3:Flooring... I was planning on installing laminate flooring, would this cause the room to be too reflective, especially if I just have the block walls?The room dimensions are 17'x12'x7.5" high or could i use area rugs to treat it?
Thank you again for your time, this place is such an invaluable rescource.
Keith

[knightfly]

1: There is about a 1/8"gap where the wall meets the slab, should I use some type of sealant here or will I increase the possibility of flanking if I seal it w/concrete patch? I'm sure there are some points where there is hard contact.

You can pretty much BET there's hard contact; I'd go with concrete patch.

2:Walls...Steve had recommended gluing the drywall directly to the block but in light of the water damage I'm reluctant to do this. Considering that the back wall is below ground exept for the top 2' would framing out a wall 1" off the block affect things considerably?I know it would be a 3 leaf wall but I would like for air to circulate to prevent mold and have insulation to keep things cozy. I would probably glue the dry wall direct on the other walls. My other thought is to not build any walls and treat the block wall with absorbers to tame the reflections.

I thought you had the water damage minimised, and good drainage? Still, one approach would be to have that wall rendered (about 1/2" of new mortar), then build a frame on the floor, screw lath across the studs on 2' centers (horizontally), stand the frame up (make it 3/4" shorter than floor to joist distance), fasten to your block walls every 4' (near the top) with neoprene mounted sway braces, fill with roxul afb's, then RC the ceiling and rock the room (1/4" gaps around perimeter, caulked as you go) - one layer ceiling, then wall, then ceiling, then wall; caulk at ALL corners as you go, forming a caulk-filled "Z" joint.

Finish with flexible vinyl inside corner bead, tape and mud, paint. The bottom plates should be bedded with 1-2 layers of either sill seal, or 2 layers of 30# building felt as a THERMAL break; keeps condensation from framing, where it won't dry with insulation against it. This is especially true for STEEL framing, but can't hurt with wood either...

3:Flooring... I was planning on installing laminate flooring, would this cause the room to be too reflective, especially if I just have the block walls?The room dimensions are 17'x12'x7.5" high or could i use area rugs to treat it?

Not a huge diff in floors, other than rugs; so it's more what you like the look of and can afford. You won't want just the block walls, unless you love the "rainbarrel" sound without the expense of a digital reverb to get it. Figure on building some absorber gobo's, and putting absorbent across most corners.

I just posted a plan for hanging "clouds" in Diet Cookie's thread...

http://www.johnlsayers.com/phpBB2/viewt ... &start=180

Steve

[musicman74]

Steve,
Is the lathe you suggest for the inside of the stud frame(towards the block wall)? Is this to prevent the insulation from contacting the block?
As far as rendering, the wall was already painted with some type of masonry sealant and I can't remove it with anything. Concrete doesn't seem to adhere too well to a painted surface. I also repainted the wall with dryloc(another masonry sealer product) after repairing numerous cracks in the mortar. I am pretty sure the moisture issues are under control but I'm still in the process of repairing the exterior crack and taking care of the grading and drainage so I want to be sure before I close things up.
I definitly don't want the "rainbarrel" effect so I'll probably end up rockin' the walls. Should I not use a vapour barrier in this case? would the dryloc be considered a barrier?(it's latex based).I also plan on getting a dehumidifier. In the interest of floorspace and cost I considered using 2x3's for framing. Will this hold 2 layers of 5/8 rock? Should I also use RC on these walls or will the sway brackets be better for decoupling?
Since I'm occupied with the foundation work right now I've got some time to plan out things to make sure I do it right.
Thanks again for all the help.
Keith

[knightfly]

Is the lathe you suggest for the inside of the stud frame(towards the block wall)?

Yes.

Is this to prevent the insulation from contacting the block?

That, and to KEEP it in contact with the wallboard for damping.

As far as rendering, the wall was already painted with some type of masonry sealant and I can't remove it with anything.

OK, no render;

I definitly don't want the "rainbarrel" effect so I'll probably end up rockin' the walls. Should I not use a vapour barrier in this case? would the dryloc be considered a barrier?(it's latex based).

I'm pretty sure it would be; I'm still working on my understanding of air barriers, vapor barriers, vapor retarders, etc; always need more time. Here's a good place for you to start -

http://www.buildingscience.com/resource ... novate.pdf

In particular, page 16 and Fig. 20, but it's all valuable info.

I also plan on getting a dehumidifier. In the interest of floorspace and cost I considered using 2x3's for framing. Will this hold 2 layers of 5/8 rock?

The dehumidifier's a mandatory thing in my opinion; for one thing, humidity is pretty misunderstood; the same identical air at a higher temperature has lower humidity (That's why they call it RELATIVE humidity) - so, your humidity may be low in the room, but near exterior walls it's cooler so will have higher humidity; this can cause lots of moisture problems, and is a good reason to keep room humidity down below 40% so the humidity at the walls doesn't exceed dew point and cause mold problems.

I don't think I'd use 2x3's for framing with double drywall; too much chance of splitting out the thinner wood and weakening the wall.

Should I also use RC on these walls or will the sway brackets be better for decoupling?

With a decoupled frame no RC should be used; your floor, and the lower part of the concrete wall, will be damped somewhat by contact with earth - so the bottom part of the wall framing will only need a thermal break (see fig.20 again) - by leaving a 3/4" gap at the top of the frame, it won't contact the ceiling joists so the only contact with structure would be through the sway brackets.

Thanks again for all the help.

You're welcome; pretty sure you'll have more questions after reading that 56 page PDF... Steve