Need some advise.

[DJL1967]

I will be extending the back of my 20x20 garage this summer and wanted some advise on what to do with the foundation. I have 10' walls and plan to extend the garage 6'X20' with 8' walls and a shed roof 3/12. I could pour a floating pad or utilize 2x6 treated framing and spray foam with 1" treated plywood flooring. I believe each scenario will be about the same in cost. The 6' addition will be my work shop but open to the garage and consist of my work bench, tools and wood storage. There will not be any vehicles on it. I've searched many forums and have come up with some ideas. Just looking for some thoughts from GJ members.
Thanks

 

[holt2ton]

I would pour a pad. Drilling re-bar holes into the side of the existing slab so that it keeps them from moving up and down independently.

 

[ducksface]

I can't begin to begin to do concrete work as inexpensively as a pro does it.
Call someone in to do the job.

 

[ard]

I will be extending the back of my 20x20 garage this summer and wanted some advise on what to do with the foundation. I have 10' walls and plan to extend the garage 6'X20' with 8' walls and a shed roof 3/12. I could pour a floating pad or utilize 2x6 treated framing and spray foam with 1" treated plywood flooring. I believe each scenario will be about the same in cost. The 6' addition will be my work shop but open to the garage and consist of my work bench, tools and wood storage. There will not be any vehicles on it. I've searched many forums and have come up with some ideas. Just looking for some thoughts from GJ members.
Thanks

Any frost considerations?

You say 'open to the garage'... How open? Any large and extensive openings in the wall of the garage may impact the shear rating of the wall.

 

[forAK]

I would think that your location would be one that will either limit or extend your options, not just uses. Pics always help.

 

[DJL1967]

Any frost considerations?

You say 'open to the garage'... How open? Any large and extensive openings in the wall of the garage may impact the shear rating of the wall.

I plan to have a span of 19' with a 3x16" LVL beam over the span. I do live up north where we get frost upwards to 4'. The existing garage slab is a floating pad and I would plan on doing the same width the extension. I've had no issues with the garage floor lifting over the 16 years since I built it.

 

[ard]

I plan to have a span of 19' with a 3x16" LVL beam over the span. I do live up north where we get frost upwards to 4'. The existing garage slab is a floating pad and I would plan on doing the same width the extension. I've had no issues with the garage floor lifting over the 16 years since I built it.

So you will remove the stud wall that carries the 19ft of load, and concentrate that load onto two posts that will sit on the slab?

Im not being a ****, just want to make sure you are seeing the possible issue. Its a garage, not a surgical suite- I get it,


Id base that 6 foot dimension on the lumber you can buy. Hate buying 8 ft joists only to cut off 2 feet on each one... (bigger is better. ) You may have other constraints, just saying.

Drill the existing slab, epoxy in pieces of rebar- tie these to the rebar int he new slab. Maybe every 18 inches- and the rebar mesh can be 18x18. Probably $60 worth or rebar.

my 2 cents

GL

 

[fountain]

So you will remove the stud wall that carries the 19ft of load, and concentrate that load onto two posts that will sit on the slab?

Im not being a ****, just want to make sure you are seeing the possible issue. Its a garage, not a surgical suite- I get it,


Id base that 6 foot dimension on the lumber you can buy. Hate buying 8 ft joists only to cut off 2 feet on each one... (bigger is better. ) You may have other constraints, just saying.

Drill the existing slab, epoxy in pieces of rebar- tie these to the rebar int he new slab. Maybe every 18 inches- and the rebar mesh can be 18x18. Probably $60 worth or rebar.

my 2 cents

GL

I am sure the floating slab is thickened or mono slab and he can buy 12' joists and cut them in half. I live up north and my garage has a mono slab that has 24" thick footer.

 

[ard]

I am sure the floating slab is thickened or mono slab and he can buy 12' joists and cut them in half. I live up north and my garage has a mono slab that has 24" thick footer.

You are 'sure'? How?

(For a second I though you were the OP....)


Yes, he can cut 12 footers in half. Unless he makes the inside of the room 6 feet, then they need to be 6' + to sit on the outer wall. Or he makes the room 5'9".... Then the roof joists- 3/12, how much soffit? Whatever- it's all good...just wanted to mention it.

 

[CNGsaves]

+1 that GJer's absolutely NEED to know Where the OP is located to give best advice. Concrete and building practices for frost heave considerations vary with weather. Same is true for insulation, etc.

UPDATE GJ Profile with a Location. Good luck.

 

[ddawg16]

My 'advice'?

It's 'advice'....not 'advise'.....

 

[Sawdustmaker]

I can't begin to begin to do concrete work as inexpensively as a pro does it.
Call someone in to do the job.

Duck is right, call in a pro and make sure that he drills into the existing foundation and places rebar like holt2ton said.