Around the house above the windows, there is a wooden beam, is it safe to make holes with a hole saw in order to install window sensors?
The 'beam' you are talking about is likely a reinforcement of the wall plate. That is, a plank of some kind on its edge. It rests in turn on notches on the standing wall studs. The distance between them should be a maximum of 60 cm, but where you have windows, the distance may be/is larger.
(You can check the thickness of the 'beam' by drilling a 5 mm hole in the middle and thereby measuring the thickness. If you find it's 45 mm, it's a plank and not a 'beam', which confirms the above assumption.)
My advice is to peek out from the inside through the window and look up towards the eave. If you have a roof truss rafter directly in view/window width, there's a high load on the 'beam'. It's not particularly suitable to make an opening for a wall socket there (for lighting fixtures), but if you can make the hole in the middle of the 'beam's height, there shouldn’t be any imminent danger of collapse, etc. If you have no roof truss rafters in view, you can pretty much make a hole anywhere in the plank/'beam', but it's still advisable to keep to the middle of the height. That is where the tensions in the wood are the least due to the load.
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Byggaren
(You can check the thickness of the 'beam' by drilling a 5 mm hole in the middle and thereby measuring the thickness. If you find it's 45 mm, it's a plank and not a 'beam', which confirms the above assumption.)
My advice is to peek out from the inside through the window and look up towards the eave. If you have a roof truss rafter directly in view/window width, there's a high load on the 'beam'. It's not particularly suitable to make an opening for a wall socket there (for lighting fixtures), but if you can make the hole in the middle of the 'beam's height, there shouldn’t be any imminent danger of collapse, etc. If you have no roof truss rafters in view, you can pretty much make a hole anywhere in the plank/'beam', but it's still advisable to keep to the middle of the height. That is where the tensions in the wood are the least due to the load.
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Byggaren
Well, here's the situation: the hole is already made. I measured up in the attic, and the beam is 100mm and aligns with the ceiling up in the attic. Measuring downstairs in the house, it's about 200mm from the ceiling to where the window starts, and additionally, the cables come up through the beam there.
The electrician drilled with a hole saw but couldn't go as deep as he wanted, so we decided to drill an 18mm hole at an angle upwards to reach the attic, which has been done on 3 windows, including the one that was hole-sawed. I went up and measured in the attic; both the hole that was hole-sawed and the one in the adjacent window are about 80 cm from the rafters and about 16 cm from the ceiling, measured almost at the bottom of the beam. In the 3rd window, the hole is about 20-30 cm from the rafters and at the same height, that is 16 cm.
What do we do now?
The electrician drilled with a hole saw but couldn't go as deep as he wanted, so we decided to drill an 18mm hole at an angle upwards to reach the attic, which has been done on 3 windows, including the one that was hole-sawed. I went up and measured in the attic; both the hole that was hole-sawed and the one in the adjacent window are about 80 cm from the rafters and about 16 cm from the ceiling, measured almost at the bottom of the beam. In the 3rd window, the hole is about 20-30 cm from the rafters and at the same height, that is 16 cm.
What do we do now?
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As I interpret your description, it’s some sort of glulam beam (100x300) or joist located in the upper wall, protruding 200 below the ceiling and 100 upwards in the attic? Or are the first 100 the width of the beam and the height is only 200?hugodog said:So this is how it is; the hole is already made, went and measured in the attic, and the beam is 100mm and aligns with the ceiling up in the attic. When I measure downstairs in the house, it’s about 200 from the ceiling to where the window starts. Additionally, the cables come up through the beam there.
The electrician drilled with a hole saw but didn't get in as far as he wanted, and we decided to drill an 18mm hole at an angle upwards so we reached the attic, which is done on 3 windows including the one that is hole-sawed. I went up and measured in the attic; the hole that is hole-sawed and the one next to it in the window is about 80 cm from the rafter and about 16 cm from the ceiling, measured almost at the bottom of the beam. In the 3rd window, the hole is about 20-30 cm from the rafter and at the same height, i.e., 16 cm.
What to do now then?
How wide are the windows? You mention that you have the hole 80 cm from the rafter on the one drilled with a hole saw and one more. The 3rd one is 20-30 cm from the rafter. If the windows are not wider than 90-120 cm, the first two shouldn’t be a problem. The one that is 20-30 cm from the rafter could be if it's not drilled in the middle of the beam, but still not an overhanging danger.
What’s done is done (with the beam) and cannot be changed now.
If it turns out later that there's any sagging above the windows (you’ll notice when they start to stick when opening), you will need to reinforce on the upper side at the eaves (as close as you can get) with unloading/reinforcement of the rafter directly above the window (a double 45x220 (approximately 2.7 m long) on edge between the rafters parallel to the one to be bypassed, with strap metal around the lower frame and these 2x45x220 and double wedges at the ends. By driving in the wedges, you lift the rafter above the window, but don’t hit the wedges too hard, as you might then push down the relieving rafters and create problems there instead).
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Builder
Made a small sketch, the beam goes down all the way to the windows, the red lines are the electrical cables that go through the beam, the window in the middle is the one that is hole-sawed, none of the electrical cords are directly under the rafter, and the holes the flex conduit passes through are 18 mm. Not a masterpiece of a sketch but maybe you see what I mean.
If it had settled, it would have been noticed quite soon, right?
there are no problems opening windows, one of the windows is a fixed window so it can't be opened anyway
there are no problems opening windows, one of the windows is a fixed window so it can't be opened anyway
I can't see much of that image and can't operate with zoom. It's fixed in pixel count.
If you have the image stored on Photobucket or some other site, upload it there first with a higher pixel count. You choose the size before you upload it.
Addition:
No. It doesn't have to be noticeable immediately. There's something called long-term deformation. That is, the building part is subjected to a constant force due to the load, changing the relationship over time. It's like taking a piece of gum and slowly stretching it. It gives way more and more until it eventually breaks when the string is stretched to the minimum.
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Byggaren
If you have the image stored on Photobucket or some other site, upload it there first with a higher pixel count. You choose the size before you upload it.
Addition:
No. It doesn't have to be noticeable immediately. There's something called long-term deformation. That is, the building part is subjected to a constant force due to the load, changing the relationship over time. It's like taking a piece of gum and slowly stretching it. It gives way more and more until it eventually breaks when the string is stretched to the minimum.
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Byggaren
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I made the image quickly in Paint and tried to change it, which didn't go so well, I'll fix it. I was thinking about the holes that are drilled, they are drilled 4 cm from the bottom edge of the beam which should be 20 high, and then angled up towards the middle on top of the beam. You can see into the hole after the holesaw about 3 cm in, and then it's just cut out maybe a cm or 2 but not notched out, if you understand what I mean. Don't you think I've blown that up a bit much, after all, they aren't that big of holes, (18mm, of which the hole from the holesaw is, hmm 70 mm and 3 cm notched out and a cm more in)
It was built in 1971, single-story house, slab on grade
I still find it difficult from the sketch to see how it is made. I also can't quite make sense of your description. And it's a bit too far between Skåne and Orust to be able to drive and see it myself, even if I was born in Malmö.
I would need a proper sketch that shows in plan, section, and cross-section how the hole cutting has been done. I'm not worried about the small holes, it's the big one for the electrical box that I'm doubtful about. So it will have to wait until sometime in the summer when I'm visiting Skåne. The house won't fall apart before then, will it?
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Byggaren
I would need a proper sketch that shows in plan, section, and cross-section how the hole cutting has been done. I'm not worried about the small holes, it's the big one for the electrical box that I'm doubtful about. So it will have to wait until sometime in the summer when I'm visiting Skåne. The house won't fall apart before then, will it?
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Byggaren
Draw a small sketch of the cross-section of the beam where it is hole-sawed.
The drill hole that goes in extends 25mm further, thus 75mm into the beam, and the notched part is 30mm + it is hole-sawed but not notched 20mm more. I hope it can be seen in the sketch, not to scale but at least the measurements are there.
So the small 18mm holes that go through are nothing to worry about, really?
The hole cutting hasn't gone all the way through but only halfway into the beam.
The drill hole that goes in extends 25mm further, thus 75mm into the beam, and the notched part is 30mm + it is hole-sawed but not notched 20mm more. I hope it can be seen in the sketch, not to scale but at least the measurements are there.
So the small 18mm holes that go through are nothing to worry about, really?
The hole cutting hasn't gone all the way through but only halfway into the beam.
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noticed that the measurements didn't add up 160+75 isn't 200 not sure if it's exactly 200mm but it's somewhere around there anyway
Now it should be correct
errm.. the doshål is probably not exactly at the bottom of the beam which it would be if you add the numbers, but as mentioned the beam could be a few mm higher than 200mm
not sure if it's exactly 200mm but it's somewhere around there anywayNow it should be correct
errm.. the doshål is probably not exactly at the bottom of the beam which it would be if you add the numbers, but as mentioned the beam could be a few mm higher than 200mm
Was the picture well imported?
I was a bit tired apparently when I made the sketch over the window and the beam, it doesn't say that the roof truss is about 20 cm in from the left on the window. (since the hole is 80 cm from the roof truss to the left, it would be 40 to the right if the hole is drilled )
I was a bit tired apparently when I made the sketch over the window and the beam, it doesn't say that the roof truss is about 20 cm in from the left on the window. (since the hole is 80 cm from the roof truss to the left, it would be 40 to the right if the hole is drilled
)
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