Do I need a membrane under my patio?
Subsequently, one may also ask, do you need membrane under block paving?
There are two types of layers, sub-grade and sub-base. A sub-base would then need to be installed before laying the paving. Weed control membranes are not essential, however if you are aware of an area with invasive weeds or roots or excavated unreliable ground, a woven groundcover or membrane would be advised.
- Paving slabs.
- MOT type 1 hardcore or sub-base material.
- Sharp sand or All in ballast.
- Fine, kiln-dried block paving sand - for jointing 10mm or smaller joints.
- Building sand - for jointing larger joints.
- Long timber straight edge - for ensuring your sub-base is level.
In this way, should I put membrane under slabs?
I would advise taking at least another 2” of soil out, a minimum of 4-5” of MOT is standard for a patio, you don't need weed membrane as weeds won't grow under the patio only in the joints if they are not grouted properly.
The short answer is: if the pavement will be trafficked by vehicles, then yes, but if it will be foot-traffic only, then not necessarily. The type of paving or surfacing that will be used is one of the key factors in determining whether a sub-base will be required.