Advice on concrete base

[Jeff]

Hi all,

I am needing to install a concrete base appox 12 feet square. The base will house a triple cat chalet (my wife fosters cats that can't be found homes). I was intending to make the base 4" to 6" thick, based on advice received. The base will sit on what is now a lawned area to the side of the house and I was thinking of a layer of broken brick/ stones etc approx 4" thick and pouring the concrete onto that. Will this be ok? Also, would I need a damp proof membrane and should this be below the hardcore or between the hardcore and concrete?

I'm a bit lost on the best way of doing this so any advice gratefully received. Regards, Jeff.

[Harry Bloomfield]

Jeff expressed precisely :

3'x 4'(?) Far too thick. 3" of concrete poured over a good layer of brick rubble should be perfectly adequate for such a light load.

[Huge]

Particularly if you put the cats *underneath*.

No need for a building, then.

[Steve Walker]

Agreed - it's an awful lot of concrete you're going to be needing Jeff.

Lot's of useful info at

[Jeff]

Hmm maybe its me but I read it as 12' x 12'

Regards Jeff ( not the OP )

[david lang]

I asume you mean 12 foot square?

12 foot square refers to a square that is 12 foot on a side, that is, 12 foot by 12 foot. 12 square feet is a measure of area. It can refer to any shape (a rectangle 1 foot by 6 foot, for instance).

Light loading for cats? 4" or hardcore & 2 or 3" of concrete will last forever.

Dave

[in2minds]

he said 12 feet square (12 x 12) not 12 square feet

[Set Square]

Eh?

It may be a long time since I went to school, but I don't think that 6 x 1 =

12 !

[david lang]

Whoops! I meant 6 x 2!!!!!!!!!!!

I'l get my coat................ Dave

[Jeff]

Thanks Steve and everybody else. It was 12ft x 12ft BTW and the cat chalet won't weigh much more than a decent size garden shed.

Many thanks for the URL, I'll have a look now.

Thanks once again everyone :-) Regards, Jeff.

[Harry Bloomfield]

Jeff formulated the question :

For that size I would stretch it to 4", depending upon the subsoil. If you are thinking of a wooden structure, then that would be much better raised off the concrete on something impermiable to allow air circulation underneath - in which case you could get away with several brick piers, instead of a concrete base.

[Harry Bloomfield]

Jeff wrote on 18/12/2005 :

I read it as 12 square feet :-)

[Set Square]

In that case, I wouldn't pour concrete at all - I'd simply prepare a firm soil base, blind it with sand, and lay paving slabs on it. that will be perfectly adequate to support your cat chalet.