Not sure where to fix now area has cracked

[Tyga11]

Hi,

I was given the advice to use M16 anchor bolts to hold a post to a patio, but the first one which I've tightened up has created a large crack.

So far I don't know if this will just be the render thats cracked (I think it's brick underneath, judging by the red dust when I drilled the hole), or if the crack is more serious.

Am I best ripping the cracked section off now, and seing if the brick needs replacing behind it, or should I leave it and try and fix another way?

The post needs to be here, and whilst I can get a fixing lower down, I'll need one where I drilled the first hole.

Many thanks,

James.

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[freddiemercurystwin]

M16! That's ridiculous! Its too close to the edge more than likely will have cracked the brick. Simples.

Find another means to support your post.

 

[Tyga11]

I did think it seemed OTT, but I'm new to all this so I went with the advice.

I'm now thinking I will use wither M10 x 150 screws and plugs, or maybe some M10 / M12 concrete screws.

What I'm looking for though please is advice with how to fix the mess of the cracked area, which is where I need to fix.

Should I replace this brick, if it has cracked, or should I use brackets or something to hold the post there is another means, so I avoid the cracked area?

 

[freddiemercurystwin]

You will need to tell us what it is you are trying to achieve not just 'I need to put a bolt in this position'. Anything screwed in in that location so close to the edge in an old weathered brick wall is destined to fail.

 

[Tyga11]

I want to fix a 75 x 75 wooden post to the side of the patio (where I have cut the slab acknowledge is where the post will be positioned).

The post will then be used to support some 1.2m fencing that will run along the top of the patio.

I will fit a total of 4 posts along the patio.

 

[Tyga11]

OK, so I got the cracked brick out and I have a replacement. I havent actually fixed it in place yet, but my plan is to do so and then render over the top, and start again!!! View media item 93878

 

[champagnecharly]

Why don't you drill into the path and not the wall? Get some post holders from screwfix/toolstation fix them to the ground and just use a longer post. If you want to fix it verticaly.. I (not saying i'm right) Would use some 10mm threaded rod drill 13mm and fill with resin.. but not so close to the edge.

 

[maltaron]

M16 Rawlbolts to fix a 3 x 3 post!!!!! beggars belief!!! 10 mm chemical anchors will be more than strong enough.

 

[Tyga11]

I'm less keen to use postholders on the ground as a) it will look less nice, and b) it will mean the posts are not flush with the side

Yes looking back M16 anchorbolts were OTT, but then they were suggested to me and they were the only size that had a long enough bolt to pass through the post.

I'm currently planning on using thunderbolts / concrete screws instead of chemical anchors, mainly for cost. I am a bit concerned they will hold strong enough though. I'm going to use 12 x 120 and put 2 on each post.

 

[Tyga11]

Actually, I might have misled on the size anyway, as the drill size was 16 mm, but the bolt itself is 10 mm I think

 

[champagnecharly]

I think you should look again at chemical studs.. It doesn't have to be that expensive stuff Tool-station do something perfectly adequate for £15 that can fit in a caulk/silicon gun .. Instead of using the expensive off the shelf you can use threaded rod cut to size. Thunderbolts arent very cheap and as you say sizes are limited. Where as thread bar.. you can make what you want the length (within reason) you want.. ...

With regards the post holder, you could cut the base flush on one side so it was flush with the wall. It would also give support in other directions. You really dont have much space on the first post to put in a 2 or 3 rods which you would ideally need.
If you do go the thunder bolt route.. Do not use hammer drill function.

 

[Tyga11]

I've been given some thunderbolts so price isn't an issue there, I'd only be tempted to change to chemical anchor if you think thunderbolts won't be strong enough?

Post holder does sound good in that it would add a lot of strength, but how hard would it be to cut the base flush on one side? I do have an angle grinder - would that be the best tool to use?

 

[champagnecharly]

Re post holder.. with a grinder like hot knife through butter.. but with a hacksaw should be easy enough.
If you have some thunderbolts and use post holder then that should be enough.. if then when all in place you notice there is too much movement because of bolt, you can always upgrade from that point.

 

[Tyga11]

OK thanks.

I would prefer to avoid the post holders I have to say. If I went for chemical anchors, would that be more possible, would you say?

With chem anchors, do i just drill a hole the size of the threaded rod, inject resin, and then put the rod in and leave to set?

 

[Tyga11]

Sorry, one more question too.

When I fixing posts that aren't close to the edge, should I use expanding anchor bolts then instead?