Basement under garage, Part II

[Bob_Skurka]

I mistakenly thought this was a freestanding garage. In my area, as I outlined above, the common walls must be firecode drywall. But we are really talking about a floor here, I would wonder if the building code in your area would allow for a NON-fireproof flooring material in the garage. I suspect it might not. You may need prestressed concrete panels for the floor material to suit codes even if wood is possible structurally.

 

[jim_wilson]

I may have missed it but I didn't see anything in your post indicating whether or not this structure was attached to your living quarters or not. If it is attached to your living quarters you can bet that the floor and walls will have to be fireproofed in some way or another. 5/8" sheetrock is called " fire rated" . If you look on either of the web sites below you will find a wealth of articles on home building and there is sure to be some info in there that will help you decide which way to go:

Fine Homebuilding

Journal of Light Construction

Weyerhauser Trusjoist

I used the Journal of Light Construction site to figure out a bunch of the engineering when I added a second floor to my house. I used the Trusjoist system for the new floor and can tell you that it is great to work with. I know I have seen installations where this system was used for a garage floor. In most cases however a layer of concrete is laid over the floor system for the garage floor. This both gives the floor some fire resistance and it also helps spread the point load of the cars sitting on it across the floor joist system. If you have a good lumberyard near you Weyerhauser in most cases will do the actual drawings for the floor system you are going to put in place and specify the correct pieces to use. I can also tell you from first hand experience that fireproofing the structure with concrete on the floor and at least 5/8" sheetrock is going to be well worth the money if something bad happens and you actually have a fire. I have a few firefighter friends and one of them actually had a fire in his own house. Once a fire starts and gets going it goes QUICKLY. Proper construction however can turn what might have been a pile of ashes and cinders and rusting car parts into a big puddle of water and some cleanup after the fire dept is gone. If you sheetrock with at least one layer of 5/8 - preferably a layer of 5/8 and another of 1/2" and then do a plaster wall you can expect the structure to stand up to any reasonable fire long enough for the fire dept to get there and prevent any real damage. Again - look at the JLC site - there are a number of articles in there about building fire resistance into wood frame structures. I believe the Weyerhauser site also has recommended procedures for fireproofing their floor systems also.

 

[yooperdave]

water beds don't put much of a load on a floor, because the load is spread out over a large area. Most floors are designed for a load minimum of 60 pounds per square foot.


Junkman, how can you say such a thing /forums/images/graemlins/confused.gif /forums/images/graemlins/blush.gif /forums/images/graemlins/grin.gif?
Most building codes specify a residential live load floor capacity of 40 psf. Some building codes will even reduce that to 30 & 35 psf for sleeping areas. Maybe the newer waterbeds have less volume of water than older waterbeds, but the weight should not be ignored.

My $.02 from your friendly professional structural engineer.

Yooper Dave

 

[boustany]

</font><font color="blue" class="small">( I may have missed it but I didn't see anything in your post indicating whether or not this structure was attached to your living quarters or not
)</font>

It was in the first thread/post:

</font><font color="blue" class="small">( "We're planning an addition to the house which will include a single car garage at living area level, and I'd like to utilize the potential space under this garage by extending the basement into this area also."
)</font>

 

[keeney]

I would go with the pre-cast concrete planks as the least hassle way of doing this.

Alternatively,
You could do a fairly thin top-coat of concrete over a wood structural frame and plywood deck. That would avoid the issues concerning plywood sagginess and burning tires on a wood floor and all. Use a rubber waterproofing membrane designed for this applicaiton like Bituthane on the wood deck under the concrete topcoat.

You could also do a cast-in-place structural concrete floor by adding enough steel and concrete thickness (engineering probably required to determine how thick, how much steel, and how much wood framing underneath). Once its cured, you could pull the wood frame and decking out and use them for the frame and decking of the non-garage part of the 1st floor over the basement.

 

[jtcweb]

I would go with the concrete planks. They are 4' wide and as long as you need them. I got a price quote of about $3500 delievered to S.E. MI for 24' x 24'.

 

[rambler]

Can you put an occupied room under a gragae in your location? Many building codes prevent this, and with good reason.

You can put the garage at the bottom & live above it. Salt, fluids, explosive vapors, overloaded vehicles tend to all go down, and I believe, if it is even allowed, you would greatly decrease the value of your house by putting in an upstairs garage.

I would not look twice at a house with a garage with a wooden floor over a living quarters - couldn't pay me to live in such a thing. Can not imagine such a thing would be legal anywhere, nor would it be wanted by anyone else. If you are allowed to do the upstairs garage, at least make it a concrete floor!

Just my thoughts.

--->Paul