Hi, I'm replacing joists down stairs as they are all rotten from damp. The damp is now cured and my new tantalised joists are been put in place, should I just sit the new joists on slate as they were before or run a timber around the perimeter and hAng new joists on joist hangers?? If I do run perimeter of timber round the outside, will this be prone to rot in years to come?? Never done this before. Thanks
you need to place dpc under the new joists,I prefer to wrap the ends of the joists in dpc,you can then level them with slates if you want,I personally use plastic packers. Then space them apart at 450mm centres and use braces to hold them in place either metal/timber straps.
keep the joists ends 50mm distance from the exterior wall.With the dpc wrapped around the joist end it eliminates any chance of rotting.To hold the dpc tight onto the joist nail it in place with galvanised nails. The 50mm distance also applies to the joist running in line with the wall.The reason for this is that it aids ventilation and damp cannot travel across to the joist.