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Rotted Floor Joists

Postby triggerfish » Wed Oct 31, 2007 9:30 am


I've just bought a late victorian end-of-terrace. I've taken up the laminate flooring that was there and replaced it with wooden floorboards. Most of the joists are fine, but there's one corner, about 1m by 2m square, where the joists have suffered from damp and are in very bad condition.

I'm going to replace them, but before I do, I'd obviously like to fix the problem. I think part of the DPC has been damaged, so I'll fix that, but I also wanted to make sure there was enough ventilation.

However, the affected area is on the corner of the house that adjoins a public footpath. This footpath is 30-40cm above the level of the flooring, so I can't put any airbricks in for ventilation. It's also a solid brick wall.

Has anybody got any tips or advice for preventing the same level of dampness in this area?


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Simply Build It

Postby LCL » Wed Oct 31, 2007 7:42 pm


It is almost certainly penetrating damp that has caused the defect you describe. Ground levels should ideally be 150mm below the DPC / floor level so that fact that it is higher, also a solid wall will ensure that penetrating damp can occur.

The best long term solution would be to try and get the pavement level reduced. You could claim nuisance, in as much as the councils high ground level is a direct cause of detriment to your property.

Make sure any new joists you install in the interim are wrapped in a dpm to prevent direct contact with moisture. You may also need to replace the wall plate as this will be in contact with the wet wall.

ventilation is a must, but not sure how this can be achieved without seeing it, especailly given the high ground level. Periscope vents are ideal for this, but not for a solid wall.

Hope this helps (even a little)

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Postby thedoctor » Wed Oct 31, 2007 8:45 pm

See our projects section and look at all the damp and dp projects. There is also a project called rtepairing structural timber. One of the companies advertising in this section is called Property Repair Systems and they offer free telephone advice without obligation.
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Postby triggerfish » Thu Nov 01, 2007 8:55 am

Thanks for the quick responses! That's all really useful.

I've never used a forum before, but it's nice to know there are people about who like to help!

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