Garage floor extension...
#1
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Garage floor extension...
I'm going to be extending my laundry room into my garage about 7 feet. Just enough to give me space for my beer fridge and a small mud room area for shoes and backpacks and stuff.
Extending the laundry room in to the garage will have to be done over an area of the garage floor that has a small step...you know, the area near the front of the garage that is commonly raised a few inches (3.5" approx).
My question(s) is/are, if I wanted to pour my own slab to match the upper level of the garage, what are some of the preparations? Will I need to do anything to the smooth floor of the garage? What types of re-bar will I need, if any, to prevent cracking/settling? Should I somehow affix the new concrete are to the old raised portion by horizontally affixing some sort of something in there? What type of cement should I use in the new area? Since I'm going to be framing up the wall over this new area, should I bury bolts in the new cement to affix the bottom of the wood frame to, or will it be ok to drill masonry lags in to it after it's cured?
The new area will be about 7'x4.
Lots of questions I know
Thanks!
Extending the laundry room in to the garage will have to be done over an area of the garage floor that has a small step...you know, the area near the front of the garage that is commonly raised a few inches (3.5" approx).
My question(s) is/are, if I wanted to pour my own slab to match the upper level of the garage, what are some of the preparations? Will I need to do anything to the smooth floor of the garage? What types of re-bar will I need, if any, to prevent cracking/settling? Should I somehow affix the new concrete are to the old raised portion by horizontally affixing some sort of something in there? What type of cement should I use in the new area? Since I'm going to be framing up the wall over this new area, should I bury bolts in the new cement to affix the bottom of the wood frame to, or will it be ok to drill masonry lags in to it after it's cured?
The new area will be about 7'x4.
Lots of questions I know

Thanks!
Last edited by funkerama; 11-16-11 at 06:36 PM.
#2
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Will you be getting a building permit for this addition? If so, check with your codes as to what is required.
I am split 50/50 between framing up the floor using pressure treated wood or using concrete. If you do concrete there is usually a two or three cubic yard minimum for ready mix concrete without paying a additional fee. Your area will be nowhere close to the minimum so you should think about whether or not you want to mix that much concrete from bags (you'll need about 27 eighty pound bags), pay the small load surcharge or order the minimum and find some use for the leftover concrete.
Yes, I would bury anchor bolts in the wet concrete or plan on drilling and installing anchor bolts after the concrete cures.
I would roughen the existing concrete floor to give the new concrete something to grab onto or better yet, drill the floor and install some anchor bolts sticking up to key your new slab to the old. Since your new slab will be fully supported by the existing floor I don't think rebar or any special concrete is required. Normal bag concrete mix is usually rated to be 3'500 or 4'000 psi when cured which may be stronger than your garage floor. Remember that new concrete is weak when new even though it has dried. You may be able to walk on it but give it as much time as possible (hopefully a month) before hammer drilling anchor bolts near the perimeter.
I am split 50/50 between framing up the floor using pressure treated wood or using concrete. If you do concrete there is usually a two or three cubic yard minimum for ready mix concrete without paying a additional fee. Your area will be nowhere close to the minimum so you should think about whether or not you want to mix that much concrete from bags (you'll need about 27 eighty pound bags), pay the small load surcharge or order the minimum and find some use for the leftover concrete.
Yes, I would bury anchor bolts in the wet concrete or plan on drilling and installing anchor bolts after the concrete cures.
I would roughen the existing concrete floor to give the new concrete something to grab onto or better yet, drill the floor and install some anchor bolts sticking up to key your new slab to the old. Since your new slab will be fully supported by the existing floor I don't think rebar or any special concrete is required. Normal bag concrete mix is usually rated to be 3'500 or 4'000 psi when cured which may be stronger than your garage floor. Remember that new concrete is weak when new even though it has dried. You may be able to walk on it but give it as much time as possible (hopefully a month) before hammer drilling anchor bolts near the perimeter.
#4
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I might be tempted to go with your idea of pouring concrete. I would trim the bottom side of the form boards to be the height you want so you can easily screed across the top. Lay sand bags or concrete blocks around the outer edge to keep them from pushing out. 3 or 4 inches in from the outer perimeter of your new pour I would use a hammer drill and set some anchor bolts in the existing slab. It should keep the new pour from ever walking away.
If you want to get started building the walls soon after pouring the floor I would insert threaded anchors when doing the concrete so you don't have to worry about cracking the new pour by hammer drilling. And, don't forget to use pressure treated lumber for your sill plate and the fasteners through the sill plate into your studs should be approved for the modern ACQ treated lumber. The copper treatment currently used can rapidly corrode plain nails if any moisture is present.
Now on to the important stuff, the beer fridge. Is it going to be just for cans & bottles or are you going to have taps? Many craft brews are now available in 5 gallon Cornie sized kegs. Most full size fridges can accommodate 4 but if you scale back to 2 kegs you can still have plenty of room for cans & bottles.
If you want to get started building the walls soon after pouring the floor I would insert threaded anchors when doing the concrete so you don't have to worry about cracking the new pour by hammer drilling. And, don't forget to use pressure treated lumber for your sill plate and the fasteners through the sill plate into your studs should be approved for the modern ACQ treated lumber. The copper treatment currently used can rapidly corrode plain nails if any moisture is present.
Now on to the important stuff, the beer fridge. Is it going to be just for cans & bottles or are you going to have taps? Many craft brews are now available in 5 gallon Cornie sized kegs. Most full size fridges can accommodate 4 but if you scale back to 2 kegs you can still have plenty of room for cans & bottles.
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Excellent advice, thanks! I'm ready to get this thing going...I have another thread going in the walls & ceiling forum before I can get rolling, but I'm almost there now
As for the fridge, in the near term it'll be primarily bottles, but I aim to have a nice little keg-or-ator in there some day
That would be so awesome
Thanks again...

As for the fridge, in the near term it'll be primarily bottles, but I aim to have a nice little keg-or-ator in there some day


Thanks again...
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Couple finer details now....
1) What type of concrete should I use?
2) Do I need to put anything in other than a few lags at the base and in the existing elevation change (horizontally)? Maybe some mesh-wire on the floor, free floating?
1) What type of concrete should I use?
2) Do I need to put anything in other than a few lags at the base and in the existing elevation change (horizontally)? Maybe some mesh-wire on the floor, free floating?
#7
Use Quikrete 5000 for your concrete mix. Comes in 60-lb. bags for less than $5 each. You'll need just under 20 bags.
Forget the mesh, unless you plan to launch Saturn rockets in there. Wasted material and effort, and not needed. You might consider buying a cheapo Harbor Freight air-operated chipping hammer (I'm assuming you already have a compressor, right?) to scarify the surface before setting your forms. And don't forget some neat (meaning no other additives) Portland cement slurry as a bonding agent, brushed onto and into the dampened surface just before concrete placement. Only put enough down (on a batch-by-batch basis) that you can cover with fresh concrete before it dries, otherwise it will act as a bond-breaker instead of promoting a good bond between new and old concrete.
After striking things off with a darby or 2 x 4, don't overwork the surface, but just let the bleed water evaporate off before hitting it with a mag float and then a steel trowel (to bring up the fines). Carefully pull the edge forms, and work some cream (thick, cement/sand slurry) into any voids present. Then hit everything with some Kure N Seal, and let it sit for at least 4 days or even a week to develop decent strength before framing and anchoring the wall(s).
Forget the mesh, unless you plan to launch Saturn rockets in there. Wasted material and effort, and not needed. You might consider buying a cheapo Harbor Freight air-operated chipping hammer (I'm assuming you already have a compressor, right?) to scarify the surface before setting your forms. And don't forget some neat (meaning no other additives) Portland cement slurry as a bonding agent, brushed onto and into the dampened surface just before concrete placement. Only put enough down (on a batch-by-batch basis) that you can cover with fresh concrete before it dries, otherwise it will act as a bond-breaker instead of promoting a good bond between new and old concrete.
After striking things off with a darby or 2 x 4, don't overwork the surface, but just let the bleed water evaporate off before hitting it with a mag float and then a steel trowel (to bring up the fines). Carefully pull the edge forms, and work some cream (thick, cement/sand slurry) into any voids present. Then hit everything with some Kure N Seal, and let it sit for at least 4 days or even a week to develop decent strength before framing and anchoring the wall(s).
#8
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Finished product, used a conglomeration of suggestions
I tiled over it, so it didn't need to be perfectly smooth.
Thanks again!
Pics here: https://plus.google.com/u/0/photos/1...40980325435041

Thanks again!
Pics here: https://plus.google.com/u/0/photos/1...40980325435041
#9
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Sierra Nevada Pale Ale, Shiner Bock, Miller High Life, Dos Equis Lager. You did not waste any time moving right in. When I saw you post again I expected to only see the floor poured. You really moved along on the project and it looks great! Thanks for the update.
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I'm not a Sierra Nevada fan, I like cheap...I mean economical Lagers, i.e. High Life, but not everyone does so I have to stock it for my neighbors
Yeah, I'm very impatient, so when I get something started, I want to get it done!
My dad helped a lot...it was fun to work, sit for a beer, work, sit for a beer, work a little, sit for another beer. I'm surprised the walls are straight!

Yeah, I'm very impatient, so when I get something started, I want to get it done!

My dad helped a lot...it was fun to work, sit for a beer, work, sit for a beer, work a little, sit for another beer. I'm surprised the walls are straight!
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Funkerama - I am looking to do basically the exact same thing to my laundry/garage, although I have the advantage of having no load bearing walls to knock out. Your pics are extremely helpful. Any tips or suggestions?
How much concrete did it end up taking?
What was the most difficult part? Any things you wish you had paid more attention to?
How much concrete did it end up taking?
What was the most difficult part? Any things you wish you had paid more attention to?