Treatment For Leaky HomesLeaky homes are rotting
The timber is wet and it is rotting. It started not long after the Untreated Pinus Radiata framing timber was introduced onto the building scene in the 1990's. This is chemical free, kiln dried Pinus Radiata. This is not a big coincidence. After all houses, have been built for years, without all these problems being so obvious before.
Before untreated framing timber, most internal framing timber was boric treated. Boric Treatment was introduced in the 50's to treat Pinus Radiata (pine) internal framing, and to a lesser extent rimu flooring, to prevent borer. Boric has some great features, it is odourless, has no skin irritability or respiratory problems and it is a flame retardant. It will also kill rot, and to a degree prevent rot as well. Boric is naturally mined out of the ground, and an essential element (boron) in soil.
So these chemical free houses started to rot and in 2002 the treatments were revised, and boron was re-introduced back into the timber framing, along with a few other treatments, such as LOSP (which there are a few complaints about). Housing construction standards have changed a bit, but not too much, but the house rotting seemed to have stopped after that time. (A coincidence? This is definitely not a coincidence) the type of cladding used in some situations could have also contributed to the problem.
What has also happened, thanks to the use of boron back into Pinus Radiata, is that the common house borer does not like it. It kills the internal yeasts, protozoas etc in the borers gut, which it needs to process its food. Therefore it dies.
This boron is not in untreated Pinus Radiata, so as we have seen many times, the pine is eaten by borer. Chemical free Framing timber was kiln dried below 4%, to prevent borer eating it, and to a high enough temperature to kill off anything living in the timber. Borer usually start into moisture above 5%, and in my experience, prefer over 7% to do well.
What happens though, is over a period of time, once the timber is in place, it absorbs more moisture, or looses moisture based on the moisture levels of its surroundings. For example in a hot water cupboard, the wood is usually far too dry to be attacked by borer. Areas such as Bathrooms, laundries, kitchens, and shady dark rooms in dampish areas, on the other hand, can have up to 11 % or more in moisture levels, and untreated doors, window surrounds, skirting boards, shelving and door frames get attacked by borer.
Treated framing timber is seldom attacked, but as anyone removing gib board, from the walls to expose framing timber, either for repairs, insulation, or , alterations , is aware, untreated framing timber gets attacked, and sometimes quite severely.
My own observations have seen examples of borer infestations in newer untreated Radiata framing. It is particularly noticeable, where extensions, or alterations are carried out, and new untreated Pinus radiata is joined on to existing infested (usually) rimu timbers. Have you also noticed, for future reference, how severe it can be in the much earlier pine garages built of untreated timber? ..
Chemical free framing timber is indicated by its green and purple stripes, and often stamped untreated.
We can treat that timber where it is accessible, with the use of Boric (Disodium Octaborate Tetrahydrate). This will not only help in the prevention of borer infestations in the wood, it will also help prevent, or kill off rot. We now also have a new product called Rot-Stop which is brilliant for stopping rot fast.
Rot is not only common in newer houses though. It happens to houses of all ages where there is a high level of moisture. Here are some photos from a house in Wadestown we looked at.