I have a very short (approx 600mm long) trimmer made up of two pieces of 120mm x 70mm timber bolted together. This trimmer is supporting timber joists on either side. If possible I would like to drill a couple of holes in the trimmer to route central heating pipes through. Now I understand the general rules about holes in joists being placed between 0.25 and 0.4 of the span from the supporting point and the holes being in the middle of the joist and the hole diameter being no more than 0.25 x joist depth. I just wondered if there was any special rules regarding trimmers? i.e. you are not allowed to butcher these?
Steve
Steve
