Hello,
We are in the process of installing ventilation and simultaneously rewiring the electricity, and we will need to make a few holes in the concrete ceiling (about 4 will be needed).
Unfortunately, we don't have a construction drawing of the house, which was built in the early '60s.
- How can we ensure that we don't mess it up?
- Is there any way to reinforce around the holes so that the structural integrity is not compromised?
Thanks
P
We are in the process of installing ventilation and simultaneously rewiring the electricity, and we will need to make a few holes in the concrete ceiling (about 4 will be needed).
Unfortunately, we don't have a construction drawing of the house, which was built in the early '60s.
- How can we ensure that we don't mess it up?
- Is there any way to reinforce around the holes so that the structural integrity is not compromised?
Thanks
P
How big holes do you need? How thick is the slab?
If they are smaller holes, max 2-300mm, you can perhaps carefully chip away the concrete and see if any large iron appears. By large, I mean iron thicker than 8mm or spaced closer than 100mm.
Please note that this is by no means an absolute rule to follow though!
-What you can do otherwise is to avoid areas where the slab is visibly reinforced in the form of thickenings, etc.
-Avoid edges + 300 in on the slab.
-Avoid drilling holes where there are supports. For example, near load-bearing basement walls.
-Avoid drilling holes around columns. Especially along/perpendicular to the support.
-Do not drill long holes across the support. (If it is supported on all four sides, you don't need to worry about this, but keep the holes as square as possible)
-Avoid drilling holes in the field. (i.e., between two supports.)
-Avoid drilling holes where the slab is weakened by something else. For example, windows in the basement wall.
The best thing is if you can get someone who knows concrete, who can look and "see" how the slab works. Don't those fixing the new ventilation or the electrician have any contacts?
Reinforcing holes can certainly be done, but one must know how to do it.
If they are smaller holes, max 2-300mm, you can perhaps carefully chip away the concrete and see if any large iron appears. By large, I mean iron thicker than 8mm or spaced closer than 100mm.
Please note that this is by no means an absolute rule to follow though!
-What you can do otherwise is to avoid areas where the slab is visibly reinforced in the form of thickenings, etc.
-Avoid edges + 300 in on the slab.
-Avoid drilling holes where there are supports. For example, near load-bearing basement walls.
-Avoid drilling holes around columns. Especially along/perpendicular to the support.
-Do not drill long holes across the support. (If it is supported on all four sides, you don't need to worry about this, but keep the holes as square as possible)
-Avoid drilling holes in the field. (i.e., between two supports.)
-Avoid drilling holes where the slab is weakened by something else. For example, windows in the basement wall.
The best thing is if you can get someone who knows concrete, who can look and "see" how the slab works. Don't those fixing the new ventilation or the electrician have any contacts?
Reinforcing holes can certainly be done, but one must know how to do it.
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I don't think it's any problem at all. We are going to cut through our concrete floor to install a staircase. The hole will be placed right between two load-bearing walls, and the engineer I had here said it's not a problem at all. Then 4 small holes shouldn't be a problem for you either. But that's just what I think.
Member
· Stockholm
· 1 397 posts
However, I wouldn't drill myself, spend money on a håltagare if you have the opportunity.
I recently had to make a 120-hole and an 80-hole for a wc and had to pay the "minimum charge" of 2500 kr, but I clearly think it was worth it considering that it was a 400 mm thick ceiling! Well-spent money...
I recently had to make a 120-hole and an 80-hole for a wc and had to pay the "minimum charge" of 2500 kr, but I clearly think it was worth it considering that it was a 400 mm thick ceiling! Well-spent money...