Basement, pit and pump room waterproofing

Where water pushes from outside

In a basement or an underground pump room, groundwater and rainwater press against the walls and floor from outside. On an existing building, the outer face is buried and cannot be reached. Negative-side waterproofing goes onto the inside face and is made to hold against water pushing from behind. It is the usual choice for existing basements and pits.

• Basements and storage rooms
• Underground pool pump rooms and balance tank rooms
• Lift pits, sump pits and service pits
• Plant rooms and other rooms below ground level

What we look at first

Where possible, we inspect the room in both wet and dry weather. We look for where the water enters: cracks, construction joints, the wall-to-floor junction, pipe and cable penetrations and earlier repairs. Active leaks are dealt with before the waterproofing goes on. Hidden problems may only appear once work starts, so repairs can go in stages. We also check whether drainage around the building can be improved and ask how the room is used, because a pump room and a storage room need different finishes over the waterproofing.

Systems we use

We choose the type of system for each room after inspection.

• Negative-side waterproofing on walls and floors where water presses in from outside
• Rigid cementitious waterproofing for structures where the base does not move
• Sealing of joints, the wall-to-floor junction and pipe and cable penetrations

Flooded pump rooms

Pool pump rooms below ground are a common problem in Phuket. When they flood, the pumps, filters and controls can be lost. Never enter a flooded pump room while the power is on. We waterproof the room, and we can also rebuild the pump room, add drainage pumps or move the equipment above flood level. Battery pumps are a last line of defence, not main drainage. Plant moved above water level needs hydraulics designed for the height. See Pump rooms & equipment. Electrical work, including drainage pumps, level controls, isolation, earthing and earth-leakage checks, is carried out by a licensed electrician agreed with the owner.

What to send for a first discussion

For a first discussion and a quotation, send us:

• Photos of the room, the damp patches or standing water, and any visible cracks
• The property location in Phuket or elsewhere in Thailand
• The approximate size of the room and how far below ground it sits
• When the water appears, for example after heavy rain or all year round