I am installing new plumbing in our house from 1920. The structure of the house consists of approximately 7 cm thick vertical plank walls and a timber sill with a dimension of 14x14 cm.
I now need to make a 75 mm hole through the timber sill to install plumbing from an extension to the main line located under the original house. Since the foundation consists of 1 m thick granite blocks, I cannot run the pipe through the foundation and am forced to run it through the sill.
My question is how can I best do this without causing settlement in that part of the house due to a weakened sill. My thought is to run the pipe under one of the doors since the vertical load should be the least there. However, complicating the issue is that the sill under the door is not fully flush with the granite foundation but only rests on a approximately 15 cm long ridge in the stone.
Should I place the hole at position number 1 or 2 according to the image?
How should I reinforce the beam? Nail plates with a 75 mm hole in the middle on each side?
In that case, I would have to lift the entire sill.. I think pushing some cement into the holes would just do more harm than good. I would need to have some kind of capillary-breaking material in between. And to get that in, I would have to lift the entire sill, as I said. The holes are exaggerated in the picture; in reality, the stone is never more than 1 cm from the sill.
I realized that I might be able to wedge flat stones between the sill and the granite blocks so that the sill has more to rest on. But back to the original question. Does anyone consider the intervention to be too risky to carry out? If so, please feel free to say so.
Have you checked how much a core drilling through the foundation would cost? It's usually not too expensive.
Going through the sill would likely mean that the drain pipe ends up a bit too shallow, considering frost and other factors. But otherwise, it's according to your option 1 where you should make the hole, as it presents the least risk for problems. And as mentioned, try to insert wedges to relieve the sill over a longer distance. Make the wedges out of wood and drive one from the outside and one from the inside towards each other, and I think it will work well.
Thank you mexitegel! When it comes to reinforcement, what provides the best rigidity: Nail plates of a thicker model or 22 mm plywood that is screwed and glued to the best of your ability?
I have some oak pieces lying around at home that can act as perfect wedges! =)
I see no reason to reinforce the syllstock at all if you arrange a good support for it. You have no forces at all where you drill the hole if you ensure that there is proper support against the foundation stones under the doorposts.
I see no reason to reinforce the sill beam at all if you arrange a good support for it. There are no forces at all where you drill the hole if you make sure that there is a proper support against the foundation stones under the door frames.
when you take almost half the thickness of any timber in a house, it should be reinforced,
Thanks for all the answers! I feel like using both suspenders and a belt when I finally make such an intervention in the construction, so I'm attaching a plywood board on both sides. I am aware that this is mainly done to prevent breakage on a hanging beam without underlying support, but it can hardly hurt.
I just discovered that the beam also has a slight tilt in the exact direction I need the slope, so I can also start drilling with a drill guide =).
I have a house from the same time with the same construction technique. Here, they haven't been too stingy when re-routing pipes in the past (the house got hydronic central heating in the 1940s and was remodeled significantly in the 1960s). They've just cut down to the right depth and chiseled out with a chisel where pipes needed to be run. It doesn't matter whether it's load-bearing or non-load-bearing parts. There's quite a bit of allowance in this type of construction. If you find a joint on the sill, it's probably a simple lap joint that doesn't withstand much force in any direction. So compared to such a joint, it is strong even with a hole in the middle.
In the village here, the area with the first houses made of grooved planks is somewhat derogatorily called "American villas" because whether right or wrong, it was believed that the construction technique came from there. And everyone knew that real houses are built of logs. You couldn't build houses out of sawn planks; they could never hold...
I would have just made incisions with the chainsaw and taken out a suitably sized hole in the middle of the sill.
