Thursday, 12 May 2011

Diary Entry No 2

The very first job that I had to tackle at 41 Swain Street was the dry rot. Many people have looked through the windows during the last year or so and seen the yellow and orange fruiting bodies with lilac coloured fringes showing above the carpet. This indicated a serious problem below and the floors had become unsafe to walk on as the dry rot had attacked the joists.

Dry rot is caused by a fungus (sepula lacrymans) which eats wood. The name dry rot is a bit of a misnomer as it requires a good source of damp to survive. The name was coined in the eighteenth century to distinguish it from wet rot which is caused simply by wet conditions. Dry rot will spread rapidly form a damp area to attack dry wood. Its fronds can pass through brick or stonework and behind plaster in search of wood to eat. It consumes all the cellulose in the wood, leaving a brittle matrix of weak material in a typical “cuboidal” manner. In the summer, the fungus “fruits” giving a bright yellow or orange display, and sends out red spores. Dry rot in occupied buildings is very serious because, not only does all the affected timber need to be replaced, but nearby timbers and plasterwork need to be removed to check its spread.

When I started to take up the floor at No 41, the pungent mushroom smell pervaded the whole house. The white fronds and cushions of dry rot filled the space between the floor and the soil below. The joists and floorboards had been almost entirely consumed, but the later (treated) timbers had hardly been touched. I was afraid that the fungus would have found its way up the stud partition wall, but on removing the plaster, I found that it had only got halfway. Another year and it may have reached the upper floor.

I removed all the timber, infected or not, from the ground floor and burnt it. Then we removed all the plaster from the walls and they are now drying out nicely. With a lower moisture level and good ventilation, any remaining dry rot will die. The floors will be replaced with solid concrete and no timber.

Ben Allen and I are now making progress on removing the cement and lime render from the outside and making the inside structurally sound. More on that next time.....