On 26/06/2019 19:05, Chris Hogg wrote:
On Wed, 26 Jun 2019 18:23:37 +0100, Andy Burns
wrote:


DerbyBorn wrote:

the regs tells me that in a 20cm Joist the max hole can be 32mm I
need to pass a pipe of 42mm diameter!

Reinforce the joist by bolting metal plates to both sides?

The any beam of that sort is in tension along its lower edge,
compression along its upper edge, as it takes load. A metal plate
along the lower edge should be sufficient, e.g. a long mending plate
or flat strap, something like this https://tinyurl.com/y3wloogy
But IANA structural engineer!

TBH slap[ping somne falss fibre n each side woul probably do a huge amouint.

I actually did this for a model plane wingh - calculated the increase in
strength of a wing with a carbon fibre strip glued along the top and
bottom of the main spar.

MASSIVE increase in strength with just a tiny amount of carbon fibre.

Wood is cheap. Its also a crap structural material.

https://www.scottsofthrapston.co.uk/...-floor-joists/

Is where things are going as wood gets more expensive


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