I was asked to look at designing an extension to an ex-local authority 1950s concrete building when I became distracted by a hole in the floorboards in the corner of one of the rooms. The skirting board next to the hole was painted white but the paint stood off the timber in flaky waves and the cuboidal pattern was obvious. With permission from the new owner I gripped the side of the floorboard at the hole and squeezed with the smallest pressure. The timber disintegrated in my hand.
I then reached under the floorboards and gripped the joist, breaking off a chunk. The timber had the life sucked out of it and was light as air and displaying large cuboidal cracking throughout. No sign of fruiting bodies, spores or mycelium but the characteristics were unmistakable. Dry Rot. I checked the perimeter of the other rooms and then went outdoors. On the opposite side of the hole in the floor an overflow pipe penetrated the to the external façade. The grey paint of the rough dash revealed whiplashes of yellow paint underneath.
The overflow must have emptied water down the wall in significant quantities and for a long period of time, skinning the wall and revealing the undercoat. The skirting board reflected severe water impact. When the flow stopped, it’s likely that while drying out would have occurred to a degree, moisture remained in the fabric. Then with the right conditions – limited ventilation and a south facing landscape window – temperatures and moisture percentages where just right for dry rot to set in.
But let’s not panic. Knowing where the moisture comes from is more than half the battle. The rest is removal of damaged timber and strict environmental controls.
These issues with buildings are the realm of the Building Surveyor. If we can assist with building defects, give us a call.