Cutting a joist

[lavinpj1]

I have a badly rotten floor joist. I've decided to cut out the rotten section and replace it with some new 3x9. The floor above is a tiled bathroom which I really cannot afford to rip out and re-tile. As such, I can't lift the floor boards above. The joist is parallel to an external wall with only about 2 inches between the wall and joist.

Any ideas how I can cut this fairly cleanly? My only current thought is a wire saw looped over the top of the joist cutting down. Any better ideas?

 

[big-all]

recip saw with long blade
osccilating saw with blade at 90% degree to body
jigsaw and finish with flush cutting blade
http://www.ebay.co.uk/sch/i.html?_f...+Dewalt+Flush+Cut+Jigsaw+Blade++Wood&_sacat=0

you will temporary have to tie say 5 joists together underneath each side and possibly acropropp to stop it moving

and a bit off 7x2 either side will normally be far easier to get in as you can feed it in fairly flat and rotate it to fit

 

[lavinpj1]

Thanks for that. Flush cut blade looks interesting. Am I right in thinking that the intention is that the blade protrudes forward of the front guard on the jigsaw such that it can cut right up to the floor boards?

 

[big-all]

yes it sits forward off the machine but you need a jigsaw where the blade goes in without rotating through 90 degrees unless you can remove the baseplate and refit with a blade in place
and without a metal guard to get in the way

 

[^woody^]

Why can't you put the new joist next to the existing one?

 

[alan333]

As per woody.... Why not leave the joist there and fit a new one beside it? Obviously make sure the rot won't continue tho.

 

[lavinpj1]

Why can't you put the new joist next to the existing one?

A large mass of cables comes through the brick next to the joist. It'd be a lot of work to reroute them.

 

[alan333]

Fit it on the other side without the cables?

 

[lavinpj1]

Fit it on the other side without the cables?

There's a 2" gap between the joist and wall. Would be difficult to get a joist properly fitted in there