Review

Damp proofing

Job description

Exterior Waterproofing

Tauranga

An external bedroom wall has been inspected after damp readings were detected and water is coming up through the block wall from the ground. Above the bedroom is a deck with no guttering and so a lot of water goes into the ground around the wall. The inspection has presented a list of recommendations for remediation that includes: Remove internal plasterboard wall lining, insulation and timber battens and dispose. • Repair crack to south wall locally i.e. grind out and epoxy repair • Install liquid-applied waterproofing membrane (e.g Ardex WPM 300) to part of the floor of the basement bedroom and adjacent storeroom. Allow to extend the membrane up to the underside of windows and approximately 500mm high up the wall in the storeroom. • Install new timber battens (glue fixed) over dpc to the internal wall face. • Install new insulation and plasterboard/timber finishes. • Install new sealant around all wall penetrations and install cover flanges to protect the applied sealant. • Dig out a trench and dispose of the ground along the south elevation approx. 500mm wide x 750mm deep. Install scoria to trench base and 100mm slotted coil drain. Cover pipe 200mm with scoria and then cover with filter fabric. • Extend the slotted coil drain to discharge to the east side of the garden. • Protect the edge of the concrete slab with a sheet material and back fill with drainage material. • Install channel drain at the wall base. Cut a chase into the wall base and install a horizontal flashing to direct water into the channel drain. Connect the channel drain outlet to the coil drain. • Install concrete path/paving parallel to the strip drain, sloping away from the wall. • Install purpose-made flashings to south east wall corner, cut and chase into the wall to protect the wall/floor junction. • Replace decayed framing within the basement store. The surveyor says that due to the fact that external waterproofing is being undertaken a building consent will be required for the recommended remedial works. It would be better if this were not so as time is against us.