Wednesday, August 21, 2013

Rotting wooden beam

Not my rot, but it looks quite similar!
Whilst the family are away on holidays I have been practising what I preach. Sleeves have been rolled up and the 1890's Cardiff end terrace is getting a bit of a once over. I will tell you a couple of tales of the coming weeks about my experiences - there are a few already!!

I will start with the unexpected one.

The house has a history and part of that was a council funded make-over in the seventies. Cheap stairs, poor re-wiring, removal of original features, concrete floors, 'damp-proofing' and a new cement render. Arrggghhhhhhh!!!

This particular post is about the joy I found when I took off the cement render on the side of the house to fix a crack in the render. Only a tiny one, but I know the issues associated with this type of fault. I cut out the render using my new angle grinder and knocked off the render, to find that the original house has a 8 by 2 beam / lintel running through the house, right up to the render finish.

The crack in the render had, of course, been allowing water in behind the render and keeping it there. This of course was then fed right into the end grain of the timber. Guess what?? Yes, a lovely rotten beam. So my little repair job has turned into a major disaster! But thankfully I know that there is a problem. Better to find out now rather than when the upper internal wall collapsed! Actually that is over dramatic as the beam is thankfully supported by some 4 by 2 uprights internally. However, this is a happy coincidence rather than good planning! If we didn't have a stud internal wall at that point (and this would be quite feasible) then the whole of the back of the house would be at very high risk of sudden failure. Not a pleasant thought.

So I have treated the wood and will be repairing it so that it should last another 120 years. However it is a clear example of how cement render can seriously affect a house structurally.

The only positive is that it is reassuring that my belief that using the right materials is really, really important when working on old properties. If the wall had been treated with a lime render then the dampness would have been kept away from the end of the beam more. I cannot blame modern materials completely, as the beam should not have been pushed all the way through the wall in the first place - 19th Century builders can be as bad as 20th and 21st century ones! However, the use of modern cement has certainly contributed to its demise.

The treated wood will now be encaptulated in a lime based render to help keep it dry and hopefully now rot free.

To come:
Render removal and French drain installation
Flat roof issues
Oak posts set in the garden

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