Shed Base: Conrete Blocks on Slabs

[Chang]

I am preparing the base for a 4m x 3m shed which is of 45mm think wall. The place I am going to install the shed is already covered with 35mm slabs on building sand (without cement mixed apparently), as shown in the picture below. Since the shed isn't that heavy, to make it easier I plan to lay 100mm 7N solid blocks in rows on the slabs to support the bearers. However, the slabs may have been there for years and some of them have sunk a little bit (up to 1cm) and one end of the patio is slightly lower than the other end. So my questions are:

1. Should I re-lay the slabs with dry mix then lay blocks, or just lay blocks directly onto the existing slabs, but using wet mix to make sure blocks are level?

2. Should I lay damp proof membranes between slabs and blocks?


Any advice will be appreciated.


Thanks,
Chang

Untitled

• Chang
• 22 Apr 2014
• 1

 

[r896neo]

bed your blocks level using a wet 4:1 mortar mix. The place for a dpc would be between the block and the shed bearer/ joist

 

[Chang]

bed your blocks level using a wet 4:1 mortar mix. The place for a dpc would be between the block and the shed bearer/ joist

Many thanks