DPM for 1ft engineering brick retaining wall?

[Tommo32]

Hi guys,

I’m building a single skin, 4 courses solid engineering brick retaining wall to retain a small garden lawn. I’ve left weep holes every 2nd brick at ground level and will backfill with 10mm pea gravel, but wanted thoughts on whether a polythene membrane should be put along the side of the wall touching the soil. Can’t seem to find any advice when using engineering brick for the whole wall but have seen this photo which talks about the need for DPM but with facing bricks (which I’m not using!).

Any ideas on whether a DPM is needed folks?

Tom

 

[KenGMac]

Tommo32, good evening.

A DPM of some sort will not go amiss given you have engineering brick a couple of layers of a good brush on liquid should assist fro some time, allow the mortar to dry first?

Suggest that to keep the 10mm gravel "clean" and free from being blocked up by small particles of earth, you totally wrap the pea gravel in a suitable Geotextile, such as "Terram" other such materials are available.

By wrapping, I mean base, both sides and wrap any remaining over the top of the pea gravel, hence it stays clean and allows free drainage.

Ken.

 

[Tommo32]

Happy Easter Ken, that’s great advice thank you, I’ll get some Apollo weed control fabric to wrap the shingle and probably will use a physical polythene DPM. The photo is where I’m at currently! Have moved onto the structure for the steps where I’m going to lay paving slabs. Any feedback on what I should put inside the square concrete footing hollows to stop the bugs congregating through the weep holes?