Can I build on top of a garage?

[Electronicpants]

Rip the roof off and put in 4 steel columns around the perimeter of the garage walls on pad founds internally (like an oil rig/mezzanine floor), steel perimeter frame connecting the 4 columns above to form your new second floor and garage "roof" and lay the joists into the steel, then you are separating any element of the original build with new, your new second floor would be a light weight design timber kit with a lathed render finish, however it may be cheaper to knock it down and start again!

Edited by Electronicpants on Thursday 17th June 11:33

[bobtail4x4]

paulrockliffe said:

Zarco said:

Terminator X said:

^^ engineers design to factor of 3 don't they so it should be able to support more load.

TX.

You think all garage foundations are designed by an engineer?

Z

I didn't think many foundations were designed by an engineer, unless there's a reason not to aren't most just width determined by wall thickness and depth to whatever Building Control want?

most/lots of BCOs are Chartered Engineers

[Equus]

bobtail4x4 said:

most/lots of BCOs are Chartered Engineers

...And of course the tables in Approved Document A (which are used to 'design' most basic strip foundations, and which BCO's will assess against) are based upon sound engineering criteria, not just random guesswork.

[TUS373]

Electronicpants said:

Rip the roof off and put in 4 steel columns around the perimeter of the garage walls on pad founds internally (like an oil rig/mezzanine floor), steel perimeter frame connecting the 4 columns above to form your new second floor and garage "roof" and lay the joists into the steel, then you are separating any element of the original build with new, your new second floor would be a light weight design timber kit with a lathed render finish, however it may be cheaper to knock it down and start again!

Edited by Electronicpants on Thursday 17th June 11:33

Thanks - sounds like a plausible idea!

[Zippee]

Mogsin said:

We had single skin garage attached to the side of our house. Wanted to build above it so got an architect in. The single skin didn’t have sufficient foundations along the outside wall.

The solution was to dig a big hole In the “weak corner” fill it with concrete then use steels (One vertical and two horizontal tying into existing strong walls).The upstairs walls were then built off the steels.

Main advantages from my point of view were that we wouldn’t need to worry about party wall changes (the wall is right on the boundary and the garage interior of the garage doesn’t loose space due to the additional interior wall.

That's what we're going to be doing to our double garage, effectively stilting the new room on steels. Obviously it's a little more involved than that but a lot cheaper and easier than the other options (digging out for double foundations or knocking down and starting again.)

[dxg]

TUS373 said:

Electronicpants said:

Rip the roof off and put in 4 steel columns around the perimeter of the garage walls on pad founds internally (like an oil rig/mezzanine floor), steel perimeter frame connecting the 4 columns above to form your new second floor and garage "roof" and lay the joists into the steel, then you are separating any element of the original build with new, your new second floor would be a light weight design timber kit with a lathed render finish, however it may be cheaper to knock it down and start again!

Edited by Electronicpants on Thursday 17th June 11:33

Thanks - sounds like a plausible idea!

I know someone who did exactly that to put a second floor on their single story timber frame. It was the only way. Quite a few more than four columns though!!!