660Z Posted February 7, 2003 Share Posted February 7, 2003 Hi all! In the next few months I plan on building a (wood framed) unattached 24x24 two car garage in my backyard. Does anyone know how deep I have to dig a trench for a cinderblock foundation? Im planning on building the walls 4-5 inches above grade for a cement floor to be poured at a much later date. Thanks Mark Quote Link to comment Share on other sites More sharing options...
blueovalz Posted February 7, 2003 Share Posted February 7, 2003 Building codes vary by region. Your most wise move is to contact the building inspector for your city or area and query him (or her) on this matter. Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted February 7, 2003 Share Posted February 7, 2003 It has to be below the frost line, but as Mr. B-ovalz said, check with the city. Quote Link to comment Share on other sites More sharing options...
Guest Aaron Posted February 7, 2003 Share Posted February 7, 2003 660Z, you may want to do something similar to what I have done/am doing (if it is possible in your location). I believe Mikelly had to go 4' down and 4' wide due to soil. I am building a 24'x24' also. My soil is hard packed clay, and the frost line is about 3 inches, so that made my life a little easier than some. I poured my slab 4" thick with a 4"x18" footer around the perimeter. I included a 1†drop from the edges to the drain in the center of the floor. It ended up taking approximately 11 yards of concrete because I did not have my site level, and a large part of the floor is 6†thick, with the footer totaling 10†thick. If I had been level, it would have used 9 yards. Last weekend I purchased the concrete blocks for 2 courses of 8†blocks, and one Cap block course. I am then going with a 10’ wall on top of the blocks. You should probably plan to have at least a 12’ ceiling so that you can add a 2 post lift someday. Here is a pic of my slab. Hopefully it will have blocks this weekend. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted February 7, 2003 Share Posted February 7, 2003 and the frost line is about 3 inches Try 3 feet in Maryland. People always complain about building inspectors, but as a homeowner I have always found them helpful. Draw up some rough sketches including things like the depth and make up of your footers and take them to the building inspectors office. They will tell you what you need to do (which is generally minimal compared to the way I overbuild things). From there you can make your own decisions. For insurance purposes you may want to go through the permit process anyway. Quote Link to comment Share on other sites More sharing options...
John Scott Posted February 8, 2003 Share Posted February 8, 2003 You might want to consider a monolithic floor/foundation. As the name implies the foundation and floor are poured in one continuous pour. Advantages are not needing a sperate foundation which usually requires two seperate pours for footing and wall, or in your case, a cinder block, and less soil is disturbed for backfill and subgrade compaction. Look into building codes in your area. Usually have to be deeper than frost line and have two strands rebar in the trenches. A reputable concrete contractor should be able to give a firm bid and know the details for your area. Too bad you're not a little closer. NOBODY puts in a better slab than my company. Flat as a mirror and smoother than any babies butt. Unfortunately over 25 years experience. John Quote Link to comment Share on other sites More sharing options...
660Z Posted February 8, 2003 Author Share Posted February 8, 2003 Hey John, what would be the price range for a 24x24 foundation like that? Can you refer anyone in the Delaware area? .....Mark Quote Link to comment Share on other sites More sharing options...
660Z Posted February 8, 2003 Author Share Posted February 8, 2003 Hi thanks for the feedback! I am going to go through the permit prosses soon just waiting to see what my bonus check will be before I start. Have to get a lines and grades survey first that going to be $1000 right there!..ouch! I spoke to a lady at the permits office over the phone about the trench and she didn`t know but i`ll ask again when I get all my blueprints and paperwork together. Just trying to see what im in for before hand...Mark Quote Link to comment Share on other sites More sharing options...
Mikelly Posted February 10, 2003 Share Posted February 10, 2003 Yup, my footers were ridiculous. 42 inches deep and 24 inches wide. I used 110 TONS of gravel... That is NOT a mis-type. I have a 6 inch slab and 5 courses of block ontop of the rebar inforces footer. We dug the footer 42 inches and then filled 32 inches deep with #57 stone. Talk to your inspector and GET A SHRINK SOIL TEST done before you even think about doing anything. In my case, it cost me an additional $4000-5000 to have this issue resolved... That cost was with ME doing the work... Couldn't imagine what it would have run with someone else doing the work. Forgot to mention, mine is 24X32 with a second story bonus room of 11X32. I used a 12 foot X 8 foot door. Mike Quote Link to comment Share on other sites More sharing options...
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