Hello
I'm going to reroute some pipes and I'm wondering what would have the least impact on the strength of the floor/ceiling joists (45*215 cc600).
I see two options;
Either 4 x 28mm holes in each joist or 2 x 34mm holes in each.
Which option is better?
What cc between the holes?
I will need to make holes in about 8 joists, could this be a problem?
Grateful for any answers.
I'm going to reroute some pipes and I'm wondering what would have the least impact on the strength of the floor/ceiling joists (45*215 cc600).
I see two options;
Either 4 x 28mm holes in each joist or 2 x 34mm holes in each.
Which option is better?
What cc between the holes?
I will need to make holes in about 8 joists, could this be a problem?
Grateful for any answers.
Holes in the center of the rule marginally affect the strength. Several small holes, a bit apart from each other, are probably better than 2 large ones.
In ceilings/floors, they are usually called beams ;-) (you know, bjälklag)
I vote for 4 pieces of 28mm placed in the middle of the beam and preferably near the support (outer wall?). I would think there should be at least 10 cm between the holes to prevent the beam from splitting along the holes due to the shear force at load.
Otherwise, a small piece of nail plate between each hole would probably also protect against splitting.
I vote for 4 pieces of 28mm placed in the middle of the beam and preferably near the support (outer wall?). I would think there should be at least 10 cm between the holes to prevent the beam from splitting along the holes due to the shear force at load.
Otherwise, a small piece of nail plate between each hole would probably also protect against splitting.
I'm pondering a bit;...
IF you make the holes right at the support, wouldn't it be possible to make "very large" holes without compromising the strength?
In the middle of the span, the bending forces are the greatest on the beam, but closest to the support, it's basically only a vertically directed shear force.
Is there anyone who supports me in this opinion/thought?
pfl0g: Don't make any big holes until at least a few others agree!!!
IF you make the holes right at the support, wouldn't it be possible to make "very large" holes without compromising the strength?
In the middle of the span, the bending forces are the greatest on the beam, but closest to the support, it's basically only a vertically directed shear force.
Is there anyone who supports me in this opinion/thought?
pfl0g: Don't make any big holes until at least a few others agree!!!
This text comes from Login page - TräGuiden
Caution should be exercised when making notches and holes in a load-bearing beam. Notches or holes not shown on the drawing must be approved by the responsible engineer before they are executed on-site. If in doubt, a control calculation should be carried out. By coordinating the frame and installations for HVAC and electricity, openings can be avoided. The guidelines here are rules of thumb and refer to joists made of structural timber. Manufacturers of glulam beams, LVL beams, hybrid beams, and composite elements have their own instructions for notches and holes. At supports, certain notches or holes can be made in the upper part of the joist, see the table. In the lower part of the joist, notches and holes should be avoided along the entire joist. If no notches are made simultaneously in the upper part of the joist, certain smaller holes may be allowed in the lower part. However, the bottom edge of holes should be placed at least 40 mm from the bottom edge of the joist. Holes should not have a diameter larger than 40 mm. They should be placed at a minimum distance from the support, corresponding to at least half the joist's height, h/2. If more than one hole is required, the center distance between the holes should be at least 300 mm. Holes with a diameter smaller than 20 mm can be placed closer together - but with a minimum center distance of 60 mm. No more than four holes should be placed in a row, and there should not be a knot directly under the intended hole. When maximally utilizing, consider reinforcing the joist with scabs made of, for example, plywood or structural timber. Holes with a diameter greater than 40 mm should be placed with the center in the middle of the joist (h/2 = neutral axis), but not closer to the support than twice the height of the joist (≥ 2h), and not near the mid-span, where bending moment is greatest. The hole diameter must not exceed half the joist's height (h/2). If notching at the support in the upper part of the beam and holes in the lower part are required, the notch height must not exceed h/4 and the hole diameter must not exceed h/10. The length of the notch may not exceed the value in the table. If the table values are exceeded, reinforcement measures must be taken. Drilling should not be done within a safety distance of 75 mm from the subfloor considering the risk that a pipe running through the proposed openings may be damaged during future repairs. If this safety distance cannot be maintained, pipes should be protected with, for example, steel.
Caution should be exercised when making notches and holes in a load-bearing beam. Notches or holes not shown on the drawing must be approved by the responsible engineer before they are executed on-site. If in doubt, a control calculation should be carried out. By coordinating the frame and installations for HVAC and electricity, openings can be avoided. The guidelines here are rules of thumb and refer to joists made of structural timber. Manufacturers of glulam beams, LVL beams, hybrid beams, and composite elements have their own instructions for notches and holes. At supports, certain notches or holes can be made in the upper part of the joist, see the table. In the lower part of the joist, notches and holes should be avoided along the entire joist. If no notches are made simultaneously in the upper part of the joist, certain smaller holes may be allowed in the lower part. However, the bottom edge of holes should be placed at least 40 mm from the bottom edge of the joist. Holes should not have a diameter larger than 40 mm. They should be placed at a minimum distance from the support, corresponding to at least half the joist's height, h/2. If more than one hole is required, the center distance between the holes should be at least 300 mm. Holes with a diameter smaller than 20 mm can be placed closer together - but with a minimum center distance of 60 mm. No more than four holes should be placed in a row, and there should not be a knot directly under the intended hole. When maximally utilizing, consider reinforcing the joist with scabs made of, for example, plywood or structural timber. Holes with a diameter greater than 40 mm should be placed with the center in the middle of the joist (h/2 = neutral axis), but not closer to the support than twice the height of the joist (≥ 2h), and not near the mid-span, where bending moment is greatest. The hole diameter must not exceed half the joist's height (h/2). If notching at the support in the upper part of the beam and holes in the lower part are required, the notch height must not exceed h/4 and the hole diameter must not exceed h/10. The length of the notch may not exceed the value in the table. If the table values are exceeded, reinforcement measures must be taken. Drilling should not be done within a safety distance of 75 mm from the subfloor considering the risk that a pipe running through the proposed openings may be damaged during future repairs. If this safety distance cannot be maintained, pipes should be protected with, for example, steel.