Let’s face it, land is always getting more expensive.
I have a few rental properties that need garages, and you just never see living space BELOW the car parking spots. I figure I could add a lot of value with good design and big windowells.
Of course it could be done safely, but maybe not economically. Has anyone done it or know of a project?
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It's been disussed here several times. you may or may not be able to find threads about it with our search engine.
I think the consensus has been that spancrete is the best overall solution.
A: You take your cleats off before jumping on the trampoline.
I'm telling Scott!
He'll love it!SamT
Anyone who doesn't take truth seriously in small matters cannot be trusted in large ones either. [Einstein] Tks, BossHogg.
It would be a lot of work and expense to do such a thing. You would probably have to build a steel support structure, then build forms with plenty of jack posts to support it. It would take a lot of rebar and the slabs would have to be a least 8" thick.
Hambro and or Speedfloor systems will work, as well a a conventional formed structural slab.
I have a design for a small suspended slab thats 6 1/2 inches thick.
Integral re-inforced concrete beam. Minimal columns. 24 ft x 24 ft oa.
I think it is very smart thing to do.
I framed three townhouses last year on a lake, all three had living space under the garage. Rough dimensions were 20'x20' or so.
They put the prestressed concrete panels in, then poured a 4" slab on top of the panels.
Good idea for small lots where space is at a premium.
When people don't know what you're about,
They put you down and shut you out.
We did several like that when I was back in Iowa. Used precast panels with a regular 4" pour on top of that. It worked great.
The only thing that got annoying was that on one of the houses when it rained before the roof was on the hollow parts of the precast filled up with water. Now I'm not sure why, but it took months for all that water to drain out of there. The electrician was drilling a hole for a tapcon to attach some conduit on the ceiling and all of a sudden he was taking a shower! scared him to death. he thought he had hit a water pipe or something.
I don't remember the exact prices, but I do know they don't just give those panels away.
I did the same thing in Iowa using Flexcor 10"deep to span 28' then 4" pour of light weight concreate on top.
Be sure you pour walls with 6" ledge to set them on. DO NOT set them on top of walls as that will leave the core ends open & they will be hard to cover and will leak.
We had a problem with cracks developing in the overlay that leaked snow melting from car wheel wells. Finally had to hang a "K" gutter under the crack to collect the melt.
Also you cannot structuraly load the interior,: that is, no load bearing walls or posts.
Except for that it made a great shop & mower storeage and where you had to have deep frost footings was no more expensive than filling the hole for a slab.
Its a great idea and the cheapest square footage you can add. Think of it this way. Without it, you still have a 4' stem wall down to the footing, and you're buying the slab. With it, your wall only grows the other 4 or 5 ft to full height, the slab goes on the floor down there, and the rest of it - prestressed panels, installed, topped, you can get here for about 8 bucks a sf. Your up front costs for the square footage when compared to the rest of the joint, no brainer.
I've been in a couple. Very nice, usable space. And pretty quiet. Makes for a great shop area if you're into that.
Real trucks dont have sparkplugs
i have a house with a basement under the garage. done with prestress concrete with a 4" floor over it. below is a workshop area. if you wanted living area you would have to plan on the prestressed beam hanging down 2' ,so you would need to dig a little deeper for basement floor. great thing about it you can make all the noise you want nobody can hear! larry
hand me the chainsaw, i need to trim the casing just a hair.
My 2-car garage has a structural floor, underneath which is a heated workshop.
I didn't have as good a source for prestressed hollowcore planks as I would have liked, so we did it instead with a deckform product called lite deck.
Sold in two-foot width sections by various depths, and any length you need, they are a mold-formed plank made of EPS with co-molded C-section steel reinforcement. With tongue and groove edges, they join together to make your deck's form, and each plank forms a T section.
Your deck thus has a T web every 24 inches.
For me, the beauty of the Lite Deck was that the ceiling for the shop underneath was pretty well insulated, the EPS foam affording pretty high R.
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Edited 3/7/2007 10:07 pm ET by Gene_Davis
That system sounds interesting Gene, do you know how far it can span?
thanks,
Mike
Discuss it with them, Mike. I used 10" panels to do 24 feet. Photos at the website show deeper panels going longer spans.
This is the stuff that I have used several times.
http://www.eagleprecast.com/home.html
Sam
As I said in my earlier post, my first choice was to use a hollowcore precast plank, like what you do.
But then I came onto the Lite Deck product, and started to cost things out.
They both need a reinforced slab on top (the LiteDeck topping is poured monolithically with the "beams"), so that cost washed out.
I wanted to get plenty of insulation below, then electrical runs for lighting, and a sheetrock ceiling, and went crazy figuring how I could do that with some degree of cost effectiveness if doing the planking.
Guys, thanks for all the suggestions. Gene, did you have to hang sheetrock on the ceiling to cover the EPS by code?Here's another benefit: with the garage in back, and the city sewer in back, I'll never have to dig up the line to make future repairs. ($6k was my best estimate so far to replace 10' of pipe)
Yes, it is sheetrocked, and the work is made easy because you've got those C-channels for fastening, running on 24" centers.
For our 24' span, we used the 10" thick deckforms, and the slab thickness at top goes from 5-1/4" at the four edges, sloping in to a 3-1/2" thickness right at center drain.
For the pour, we built temporary 2x4 framed walls at the third-span points underneath, as shoring, and then knocked them out after two weeks of cure.
The slab is finished with a Sonneborne 2-coat deck membrane system, consisting of a primer and topcoat, each going on at 40 mils wet, each being a two-component moisture curing urethane. The top finish has granulated rubber particles, about the texture of sand, sprinkled in when wet, then backrolled, to give it a no-slip texture.
We are in snow country, and the cars come in with 100 pounds of frozen slush on them, which translates to a lot of water melt, none of which we want below.
The Sonneborne system is meant for deck waterproofing, such as for parking garages, and is just the ticket.