Concrete garage Base

[pippo]

Hi all,

I am looking into building a steel framed then galvanised cladded garage which is to replace an old timber garage. For this I am going to lay a concrete base down. I intend on bolting the frame to the base instead of concreting it in.

The base will be about 5.5m x 3.5m. Have dug down about 6" so far and the soil seems to be quite tough.

Here is where I am looking for some advice:

1) What depth would you recommend for the hardcore? I will be puting sand and DPM on top.

2) What depth and mix of concrete would you recommend? it will only have 1 family sized car in it at any 1 time.

3) Should a base of this size be sectioned for movement gaps?

4) How many bags of cement/sand gravel would be required for the recommended depth so I can roughly price it up? Would it be cheaper to have a ready mix truck pump it in? (Its about 20m from the road)

Thanks in advance for any advice you have.

Pippo

 

[noseall]

1) What depth would you recommend for the hardcore? I will be puting sand and DPM on top.

100mm compacted mot.

2) What depth and mix of concrete would you recommend? it will only have 1 family sized car in it at any 1 time.

100mm will stand a car but the edges of the slab may need thickening. Mix the concrete 6 parts ballast to 1 cement.

3) Should a base of this size be sectioned for movement gaps?

no

4) How many bags of cement/sand gravel would be required for the recommended depth so I can roughly price it up? Would it be cheaper to have a ready mix truck pump it in? (Its about 20m from the road)

Personally i would have 4 tonne of ballast and 25 x 25kg bags of cement and mix it myself. It is a two man effort - one to mix the other to barrow and lay. But i own a mixer and have experienced manpower.

Otherwise you will need 2 cubic metres of concrete delivered. You will pay more for part load but there are concrete suppliers who bring their own ballast and cement and mix quantity to order. Some provide a barrowing service too.

A concrete pump should cost between £170 and £250. Most charge a fixed fee for the first hour plus additional waiting. Some will only start the clock once their tubes are set up. You will need a bag of cement to prime the pump and they will need access to water too, i.e. a garden hose.

 

[pippo]

Excellent reply noseall thanks.

Would 150 be enough around the edges? I think there will be 8 posts bolted to the base and will be a fairly light construction.

Pippo

 

[noseall]

150mm sounds good.