Hello!
I am going to build a bridge that rests on wooden trestles based on the following: http://www.byggvarulistan.se/byggprojekt/bygga-brygga-pa-bockar/. For the trestles, 45x95 pressure-treated timber and 34x95 are used. The bridge will be in a lake and most of the trestles will be in constant contact with water, and as I understand it, NTR A is recommended. The problem is that all building suppliers only seem to have NTR A from 45x145 upwards, while smaller dimensions are always NTR AB. Is it possible to get 45x95 NTR A? Would it work to use NTR AB nevertheless? I would like the trestles to last five years or more, at least.
Regards,
B
I am going to build a bridge that rests on wooden trestles based on the following: http://www.byggvarulistan.se/byggprojekt/bygga-brygga-pa-bockar/. For the trestles, 45x95 pressure-treated timber and 34x95 are used. The bridge will be in a lake and most of the trestles will be in constant contact with water, and as I understand it, NTR A is recommended. The problem is that all building suppliers only seem to have NTR A from 45x145 upwards, while smaller dimensions are always NTR AB. Is it possible to get 45x95 NTR A? Would it work to use NTR AB nevertheless? I would like the trestles to last five years or more, at least.
Regards,
B
Timber that is in constant contact with water should be of the type NTR/M. Go to Beijers or a similar large building supply store, they usually can order most things, even if it might cost a little more.
Yes, the easiest way is probably to go to the store and ask, of course. I had understood it as NTR M applies on the west coast to sort of protect from pests but that NTR A suffices in inland waters and along the east coast?
I don't have the expertise to discuss this, but there is definitely a difference between the west coast and the Baltic Sea. Here in Blekinge, we usually use oak, it is guaranteed to hold. However, I stand by the tip about Beijers for other dimensions.
Otherwise, you could split a 195 as well.