The Brew Cabin

Posted: **Fri Aug 09, 2019 5:04 pm**

Should I start filling up this 35mÂ² excavated garden with a sharp sand base now, or does it need more MOT Type 1 aggregate laid roughly up to the top of the breezeblock foundation level first?

Once a sandbase is laid I will then be laying 38mm depth paving slabs aligning to the top of the lowest black brick?

I ask as I have excavated my patio too deep and 50mm of MOT Type 1 has only come up so far:

Posted: **Fri Aug 09, 2019 9:37 pm**

Your about 100m off your finished level from the looks? 40mm slab and bed 65mm so bit shy still. Stone cheaper than compo

Posted: **Fri Aug 09, 2019 9:37 pm**

Sorry dry bed? See tonys pages for thickness

Posted: **Sun Aug 11, 2019 5:52 pm**

50mm of "MOT" is nowhere near sufficient. The minimum usable depth of a DTp1 (the correct name for what you call MOT) is 100mm. Read why here

So: 38mm flags + 25-40mm mortar bed gives you a pavement layer depth of 63-78mm. You want to be 150mm minimum below DPC, so your sub-base should be around (150 + 70) 220mm below DPC.

The Brew Cabin

Does this subbase need more mot type 1 or sand?