How do you check damp proof membranes in Qardho?

Damp proof membranes supervision gaps in Qardho come down to timing: the sheet is covered before anyone has recorded whether its laps, corners and pipe penetrations were sealed. Ground moisture ingress can then appear as rising damp, salt staining or damp screed edges. Once the slab or floor is in place, the membrane itself cannot be inspected, so the checks have to happen before the pour.

What does the membrane do on a Qardho build?

The membrane separates the building from moisture in the ground and from salts carried in soil and groundwater. It works as a continuous barrier, so one gap or unsealed penetration lets water track under the sheet and into the slab. General practice is a lapped sheet with taped or welded joints and a thickness set by the design; ask the project specification or the design engineer for the lap, thickness and joint method that apply. Sheet can soften and wrinkle if it sits in sun or heat for long, so confirm how the contractor plans to lay and protect it, and check that the work follows the plan. Ask the municipal engineer's office what records, if any, exist for the plot, since ground conditions affect how much moisture the barrier must resist.

How do weak supervision and missed inspections lead to ground moisture ingress?

Weak supervision lets the sheet be laid and covered without anyone checking the details that decide whether it works. A wheelbarrow is dragged across the membrane and tears it; a pipe passes through with no collar; a lap runs narrower than the specification requires; the sheet stops short at a wall and the screed bridges over it. Once covered, none of this can be seen again: the membrane leaves no record of its laps or penetrations unless someone recorded them first. Verify the conditions on your own project by asking for the pre-pour photographs and the inspection record. The fix is a hold point. Nobody places concrete until the supervisor or the client's representative signs off the membrane as laid.

How do you check the work before it is covered?

Walk the membrane with the contractor's foreman before any concrete or screed goes down, and stop the pour until defects are corrected. Check that the surface below is compacted and blinded, that the sheet is unbroken over the full footprint, and that laps run in the direction that sheds water, not against it. Look at every penetration: water pipes, drainage, conduits and starter bars. Each needs a sealed collar or taped sleeve, and upstands at walls and columns should rise above the finished floor level as the specification requires. Photograph each corner, lap, penetration and upstand in sequence, then sign a dated record that names the location and the person who checked it. Keep that record with the pour approval, so a later damp complaint can be traced to a drawing and a photograph rather than memory.

What to do next

Set a membrane hold point in the inspection plan for the build. Write the lap, thickness and protection requirements into the specification, name the person who signs the pre-pour check, and require dated photographs with the sign-off. On the next pour, walk the sheet before the concrete truck arrives, and ask the named sign-off person to complete the dated pre-pour record before the pour is scheduled.