19/05/2026
Go to your site right now. Look at what's underneath your DPM. If it's sitting directly on sharp hardcore β you don't have a waterproof barrier. You have a sieve with a concrete lid.
Swipe through π and find out why the bottom of your walls will start crying in about 18 months β and the one step that costs almost nothing and stops all of it.
Save this before you reach substructure stage.
Drop "DAMP" in the comments and I'll send you the full compliance checklist directly to your DM.