Concrete shed base

lfp

In the next few weeks I'll be doing a concrete base for a metal shed (9'10ftx9'10ft). The base will be about 11ftx11ft.

I've mixed concrete before and am pretty content with lining up the timber frame for the base.

My dilemma is that I have a pretty large pile of sand left over from my house build and a pretty small pile of gravel! I would usually mix a base/path/post mix at 1:2:4 (cement:sand:gravel). As I'm low on gravel and have loads of sand would it be safe to mix 2 parts gravel and 4 parts sand??? I also have reinforced steel left over from the house foundations and floors which I intend putting in the shed base.

Buying a few bags of gravel will cost an awful lot and I don't want to go through the headache of getting a small delivery of gravel as it will be as unsightly a pile as the sand and while way cheaper than the bags I will probably only need a portion of it!

Martron

the extra sand will lower the overall strenght but you should be able to get a better finish.

if you increase the cement ratio also combined with the mesh you should be ok

lfp

Thanks man.

Good suggestion on the cement, I'll get an extra couple of bags to bring up the overall ratio.

Not to worried about the finish to be honest. Just putting up a cheap metal shed to keep fuel (timber, coal etc.) dry and the odd few tools.

Jasleigh

Any advice for building a concrete base over a river?
There is a span of 3 meters and a retaining wall on the far side of the river. Its at the bottom of a large back garden.
Loads of space for a shed/office. The river can swell but hasn't flooded in 80 years. River is 1.7m below back garden.
I've no idea where to start or what to do. Any advice greatly appreciated.

landcrzr

Jasleigh wrote: »

Any advice for building a concrete base over a river?
There is a span of 3 meters and a retaining wall on the far side of the river. Its at the bottom of a large back garden.
Loads of space for a shed/office. The river can swell but hasn't flooded in 80 years. River is 1.7m below back garden.
I've no idea where to start or what to do. Any advice greatly appreciated.

A bridge?

Bonzo Delaney

Jasleigh wrote: »

Any advice for building a concrete base over a river?
There is a span of 3 meters and a retaining wall on the far side of the river. Its at the bottom of a large back garden.
Loads of space for a shed/office. The river can swell but hasn't flooded in 80 years. River is 1.7m below back garden.
I've no idea where to start or what to do. Any advice greatly appreciated.

How strong are the retaining walls

2x hollow core floor slabs on pads spanning the area should do then pour a screed over.
The important bit is what their sitting on.
Engineer territory