JWL's studio construction

Still feverishly packing. Did a couple things recently, though. First I changed the locks on the garage.... and I have a set of locks to put on the front door of the house. Got too dark before I could change it. Second, I measured the inside of the garage, inside the studs are 11.5'x18.5'x8'. A bit smaller than I thought, which is all the more reason to go with one room. Third, and perhaps most problematic, the slab that the garage sits on is CRACKED. Like, completely cracked, in 2 pieces, all the way across the garage pretty much in the dead center running across the 11.5', all the way through the concrete. IOW, the crack goes all the way to the bottom of the slab, viewed from the outside. :evil: Not sure what to do about this, or if it even matters. I'll try to take some pictures of it next time I'm there. Anyone?

first - figure out why it cracked... it could be an indication of any number of construction faults, or just nature doing its thing and reclaiming man's work in the wild... either way before adding any substantial weight (or time/money) to the building you should have a structural engineer look at it. it could be a thin slab, one without reinforcement, water underneath eroding the ground under it and freezing, etc.

jwl wrote:

Furthermore, if you connect them all together, they resonate as one, with more mass, which pushes the resonance frequency lower, which (I think?) increases the amount of energy needed to excite them.

As I recall, it does in fact lower the resonance frequency, from a "bad" range to a "worse" range. That's one of the reasons constraned dampening layer, such as Green Glue, is so effective. --Keith :mrgreen:

jwl wrote:

I'm also thinking of ways that I can leave the garage door in place, at least cosmetically (I don't expect to be able to open the garage door), for stealth reasons. A little background: back in the day I used to be a car audio installer. We would often go for "stealth" installations, which are designed to look as stock as possible. These were always my favorite. I'd like to do that for the garage, to preserve it's appearance as such. I'll have to remove the tracking mechanism, but perhaps I can leave the door sealed up in place, and put some lumber behind it to get it not to rattle?

jwl, if you were to face the back of the door with a protective membrane - perhaps a 6 or 8 mil poly - which could be temporarily attached with a spray adhesive - and then frame a wall inside of that which was slightly higher and wider than the door - (the door can be locked to the original frame with metal Z clips) and then seal and one layer of drywall over the new frame........... in fact - di it with a backwards frame and gain the air space for added iso. whew......... you could then take between the door and the new drywall and completely fill it with expansive foam - something in a 3 to 4pcf capacity....... This way the door, and the drywall would become one assembly and one leaf. Then you could frame your 2nd leaf inside of this and proceed with standard isolating constuction techniques. Sincerely, Rod

Thanks for the replies, all. We're still in a holding pattern, getting our stuff where we want it. Right now the garage is full of stuff we don't want in the house yet. I haven't had a chance to investigate the crack much more. I'll post more details here when I get them. Thanks for the writeup on beefing up the door, Rod. I'll probably be posting lightly here for the next several days as I get my house in order.... and after that I have an entire summers' worth of yardwork waiting in the wings. :roll: The studio build will come.... the first two tasks at hand are to investigate the crack and see what's up with that, and to get electricity to the building.

OK, time for an update. I still haven't checked out the crack in detail. But I think the back of the garage (ie, the wall furthest away from the garage door) is about a half-inch lower than the rest of the garage. It's also not quite level, ie, it tilts toward the back. I think it's pretty close to level up to the crack, then it tilts back. This tells me that the ground underneath shifted a bit, which caused the slab to crack. I don't know if there is rebar in the concrete or not. Does anyone know of a quick way to tell whether or not my slab has rebar in it? I can see the sides of the slab outside the building, but I don't remember seeing rebar inside. I'll have to look again. In terms of electricity, I discovered that I'm going to need to dig down 2' for the power lines. This means I need a ditch about 50' long, and 2' deep. This is a LOT of work, especially in Maine, where I'd pull up hundreds of large (meaning larger than my fist) stones by digging such a large ditch. A friend of mine mentioned a big rental tool called a "ditch witch" which I must investigate. I have pretty much settled on a design, (not to say I won't mod it further, but it's a very good start), and I'm starting to think about first steps. I'm also going to need to build a shed; our garage has quite a bit of stuff in it now. That stuff will have to go somwhere once I start the build, certainly by the time I begin inner framing (during the beefup phase I will probably be able to work around the stuff if need be).

Yes. Ditch Witch is the famous ditch-digging gas-powered tool. It can be operated by one person and it makes digging utility/plumbing trenches a breeze. I've never operated one before, but I've seen them in use many times. They're a bit like large chainsaws that cut into the ground, carrying chunks of earth up on their teeth. You'd be a fool not to use one for that task! :-) Be sure to call the national "Before You Dig" phone number a week or so before you dig... You'll then get the assurance that there are truly no utilities on your dig route, or if by chance there are, techs will mark the locations with stakes and/or marking paint. If you fail to do this, then you alone are liable for any damages, assuming the collision doesn't kill you, in which case your estate will be! Substantial variances on your concrete point to it not having rebar. As a rule, if if a concrete crack is substantial enough that you can stick a coin (dime) into it and have it stand up without holding it, it's bad and should be replaced. Advice was given about consulting a structural engineer. Actually, you should (also?) get an evaluation from a geological engineer!! Our first home was settling at one corner of the garage quite substantially, with cracks in the wall and the floor telling the tale, all visible during our escrow period when buying the place. At the advice of our home inspector, we ordered a geological survey to assess the situation and recommend a remediation strategy. It ends up a nearby birch tree's roots had obviously jostled some sections of walkway, causing a damming effect of the rainwater that came from the rain gutter downspouts at that corner. The recommendations were to have the tree and its stump removed, tight-pipe the downspouts to the street, and reset the concrete to a level state. We had a contractor do that work (on the day we were to close escrow in fact! :shock:). In your case, shoddy construction may a factor, but my money's on nature having gotten the upper hand. :roll: --Keith :mrgreen:

j Check the gutters and drainage around your building to make sure you have positive drainage away from the building. Water puddling around the perimeter could have caused some small amount of settling which could crack the slab (though not necessarily ruin it). Can you find city or county records for the garage when it was built? From your photos, it doesn't look to be old at all, and local code should tell you about rebar requirements. You shouldn't be able to see it (rebar) from the edge of the slab anyway; this would let moisture in to rust the rebar. I don't agree with Sharwards comment about the cracks in the concrete indicating the need for replacement with dime-sized cracks in it; lots of perfectly good concrete has cracks in it. Frank

Yeah, I syppose I was a bit careless with my "cracked concrete" remark. ;-) What I should have said was this: our home builder uses that criteria to determine the quality of a slab. If it has a crack thick enough to hold a coin up, then they'll repair it under the 10 year home warranty. My in-laws' builder, I think, has the same criteria. Another factor is whether or not there's an elevation change. Sorry about the careless inaccurate absolute. goldstar, thanks for calling me on it. :-) --Keith :mrgreen: