Sister joists with a single one?

[ms2004]

Hi,

Just wanted some clarification on this. We have a small hallway that adjoins a porch. There are 3 no. joists from the hallway resting on a stone foundation. All 3 joists have rotted at the ends. Either side of joists 1 and 3 are rooms with concrete floors. The concrete has been installed up against the sides of the joists so sistering them on both sides is not possible without removing the concrete.

I can quite easily get a new joist section against one side of the joists and wrap it in DPC and put it onto the stone foundation but will this be adequate? My intention was to put a 3ft approx piece of C24 timber against the joists, fix with 5 bolts in a W pattern. Is sistering on one side of a joist acceptable?

Thanks.

 

[Deleted member 174758]

Sistering on one side of a damaged/decayed joist is normal practice providing you have sufficient fixings between them (normally something like 3 no.coach bolts over 1 metre overlap). I can't see why, with what mist be a relatively small structure, it would not be possible to simply replace them, one at a time