I am going to cast three concrete footings with rebar for 115x115 posts, which will support a ledger board with a 6x5m2 patio roof. The largest pipes seem to be 200mm in diameter, which gives the rebar a distance of about 40mm to the edge of the concrete.
Question1: Is this distance (40mm) sufficient, or should I build a custom mold?
Question2: The substrate is soil about 40cm deep, then sand. I was thinking of excavating, laying down gravel, and casting in two steps with a wider base at the bottom. Rebar. How deep should I make the footings?
Question1: Is this distance (40mm) sufficient, or should I build a custom mold?
Question2: The substrate is soil about 40cm deep, then sand. I was thinking of excavating, laying down gravel, and casting in two steps with a wider base at the bottom. Rebar. How deep should I make the footings?
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The rebars are well galvanized so the concrete isn't needed for corrosion protection.
Bend the bars so they angle inward at the bottom of the concrete.
In other words, it will work with 40 mm.
How deep depends on the ground, frost, and load.
Excavate, make a nice flat bottom, place a concrete slab, and set the pipe there.
What will a bit of loosely packed gravel do better than undisturbed ground?
Protte
Bend the bars so they angle inward at the bottom of the concrete.
In other words, it will work with 40 mm.
How deep depends on the ground, frost, and load.
Excavate, make a nice flat bottom, place a concrete slab, and set the pipe there.
What will a bit of loosely packed gravel do better than undisturbed ground?
Protte
Hello protte. Thank you for your response. Regarding the plintjärnen, it was the stability that was meant, that is, what is the minimum distance to avoid the risk of breaking. Concerning the gravel, I have read that it is good from a drainage perspective, but do you think one should avoid it?
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With a screwed-in post, it's only a downward force. If you're nervous, attach the metals to a piece of post and wrap galvanized wire 10 times around the metals so it goes down into the concrete. Threaded rod between the metals down in the concrete also works.
If it's for drainage, the water must be able to flow out to a ditch or another stormwater pipe. A hole is a hole.
Protte
If it's for drainage, the water must be able to flow out to a ditch or another stormwater pipe. A hole is a hole.
Protte
Can anyone provide a good answer on how to allocate the length of mounting brackets?
I have some that are 50cm and was thinking of placing the bolts in the post at 5 and 15cm above the zero point. This roughly means that 30cm of the mounting bracket should be in the concrete. Should I move the bolts higher or keep as much as possible in the concrete?
I have some that are 50cm and was thinking of placing the bolts in the post at 5 and 15cm above the zero point. This roughly means that 30cm of the mounting bracket should be in the concrete. Should I move the bolts higher or keep as much as possible in the concrete?
If you read Joma's guide to construction fittings (http://joma.se/file/handbook-2013.pdf), you can see on pages 251-252 that the post irons should be embedded at least 200mm in concrete of quality C25/C30. The distance between the concrete and the first through bolt should be at least 60mm for a 6mm bolt, and 80mm for an 8mm bolt.Bösahus said:
In short, the depth is ok, but not the distance to the first bolt. However, if you put 25cm in the concrete. But one must consider that this is a manufacturer's advice for their own product, not an industry standard (as I understand it).
As protte writes, it's not as crucial if it's a patio roof anchored to the house or similar (torsionally rigid). You can use post shoes if you wish. If it's a roof or fence or something that needs to absorb lateral forces (moment), it's important to use double foundation irons with proper distance from the end grain and sufficient embedding.
In my case, it's about gate posts, so I'll probably raise my plinth irons a few cm but try to keep 25cm down in the concrete.
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Bösa: Sounds like a good plan, gate posts (if you have gates) take a lot of wear. You see many fences and gate posts mounted with post shoes or similar that lean. A bit of iron in the footing and a good grip in the screws is needed...
Yes, now the gateposts are sitting like a knife in the farmer!
However, I might have become a bit regretful when I set the posts a few millimeters down into the concrete, as they might rot. Maybe I can chip a small channel where the water can drain out and air can get in to dry.
However, I might have become a bit regretful when I set the posts a few millimeters down into the concrete, as they might rot. Maybe I can chip a small channel where the water can drain out and air can get in to dry.