Increasing depth of loft joists

Postby gasgeezer » Tue May 01, 2007 5:24 pm

All, I'm looking to increase the depth of my loft joists to allow deeper insulation coverage. Currently the depth is 100mm but want to increase them to accomodate upto 250mm. Should I lay the new wood @ 90 degrees to the existing ones or should I attach to them directly in line.

I was hoping to strengthen the existing ones as they have in the past had woodworm activity & some do actually resemble a fine swiss cheese in places but are still quite solid.

I will them place loosefill insulation in the voids created & chipboard T&G flooring on top to created a cover for storage.

Any suggestions
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Simply Build It

Postby vark » Wed May 02, 2007 10:18 am

Treat the joists first with 5 star wood preserver to prevent further rot. Run new joists at 90 degrees and transfer all cables etc to top of new joists. Box round all light fittings. No electrical equipment should be covered by insulation.
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Postby Newbee » Fri May 11, 2007 9:35 am

I did my loft last year and had to raise my joist depth as well, I had a problem with cables as well the shower cable was fitted is such a way preventing me from lifting it so I created a void when laying the insulation and was able to lay again across the top of the void so that the insulation did not touch the cable. As for the lighting and cable sockets I was unable to move these as well but these are not so important as the heavier cable so I covered them.
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