Cure for waterfrontage under water
April Showers Waterproofing carried out waterfront rectification under instructions from the Office of Fair Trading on this home converted from an old boatshed. When this old boatshed was converted to a dwelling with an extra bedroom wing added, the builder missed the point that houses should be drier than boatsheds! The boatshed was slab-on-ground with solid masonry walls and a gable roof.
By removing the roof and replacing it with a slab, a very pleasant deck was created to observe the passing parade of watercraft.
The two storey addition was timber frame with a corrugated colorbond steel roof. All of these materials have different movement rates and when they interact the stresses at junctions are significant. Waterproofing takes on a critical significance and should be carefully researched. However, if the correct membrane and installation details are chosen the end result will always be a long lasting low maintenance outcome.
However, the builder failed in a few key areas, namely:
- Did not overhang the slab to create a drip edge for the slab, allowing water to run
directly into the solid brickwork. - Only provided three 20mm drains through the edge hob upstand to drain 35 Sq.M. No overflows were fitted.
- Failed to over-flash the timber lining boards of the two storey addition onto the deck.
- Provided no sill flashing of the access door onto the deck.
- Carried out his own waterproofing. His claim for a variation for the waterproofing established that he bought enough resin for 25% of the recommended coverage for one coat. The recommendations from the manufacturer’s Data Sheet specify a primer, and two coats. The builder applied no primer. The builder applied no reinforcing at upturns and/or joint.
