Concrete Slab and Floor base

[Steve111222]

Hi,

Had a couple of questions on building the concrete floor base for my extension to my house. we have already built up to DPC level brickwork now so next going to add and compress hardcore and sand then pour concrete slab.


1) 150mm Hardcore - what is the difference between Loose Type1 Crushed Concrete and MOT Type 1? Which one should i go for?




2) We will have a fairly large area to pour, do I need to put in any expansion joints or divide up the floor at all?

total area i believe would be around 37 m2 and needs to be 100mm concrete slab..

 

[Bonni]

Avoid recycled hardcore (made from crushed brick and concrete, dreadful stuff). So 150mm hardcore, 25mm building sand, 1200g DPM, 100mm Kingspan minimum, thinner DPM sheet and 100mm concrete with freeflow added.

 

[Steve111222]

Avoid recycled hardcore (made from crushed brick and concrete, dreadful stuff). So 150mm hardcore, 25mm building sand, 1200g DPM, 100mm Kingspan minimum, thinner DPM sheet and 100mm concrete with freeflow added.

OK - thanks.

What is wrong with the crushed concrete? It is a lot cheaper (at least a few hundred pounds) than the MOT Type 1 so just want to check what the pros / cons are of each.

One of the companies I was looking at specifies this -

MOT Type 1 Crushed concrete is literally crushed concrete that meets the Department of Transport Specification for Highway Works and commonly used as a drainage solution or alternatively used for;


MOT Type 1 crushed concrete can also be constructed of other hard inert materials including Limestone, Granite or Gritsone.