Fixings for balustrade metal posts

[Andrew_xxx]

Hi
I need to find the best way to securely fix the metal posts for a glass balustrade.
The post brackets sit horizontally and bolts go through vertically. The brackets will be sitting on the edge of a raised patio. The patio is constructed of Indian sandstone slabs on a single skin of house bricks.
What do you think will be suitable fixings?
Thanks in advance.
Andrew

 

[SammyInnit]

A lot of this is marketing rubbish but that's what I'd look at.

 

[Newboy]

How close to the edge are you planning to fix?

 

[Andrew_xxx]

Hi
I have attached a photo. There is only a 2cm overhang of the slab over the brick and balustrade will run along the edge on the left hand side of the photo, fixed into the brick through the slab.

 

[SammyInnit]

Hi
I have attached a photo. There is only a 2cm overhang of the slab over the brick and balustrade will run along the edge on the left hand side of the photo, fixed into the brick through the slab. View attachment 133070

You need to fix into the masonry. I imagine that slab being deeper than that. I'd still consider using chemical fixings or rawl bolts. Rawl bold anchors can cause masonry to crack if over tightened or if the bricks such as those, have been effected by damp.

I presume the balustrade was an afterthought?

 

[Andrew_xxx]

Yes we didn't give much thought to the balustrade until now.
Those threaded bar and resin fixings which I'd never come across before, look like they should be pretty good. How deep should I put them? The metal posts are about 1m high.
Thanks for all the help.
Andrew

 

[Andrew_xxx]

Just to let you know, after further looking around, I'm going to side mount the posts as per photo and fix them using a threaded bar and resin. I think it will be stronger than going vertically down through the brick.

 

[SammyInnit]

Neither will be ideal in your case. The reason I suggest you stick with the resin fix is because of the type of trick. Those aren't engineering brick so will benefit from the tolerance offered during expansion and contraction from resin, during summer and winter. Not to mention a rawl bolt will struggle to work all that well in a hollow core facing brick, even if it doesn't split it when doing it up.

Under those slabs, is there a lot of concrete? If there's a good bed of concrete under those and behind the brick I'd be tempted to fix them on the flat surface. The corner mount will help alleviate the outward levering force applied to the balustrade when people lean on it. This in turn would be a benefit as it would be much more difficult to pull that rod out of solid concrete than it would out of a facing brick thats acting as a retaining wall for soil or aggregate.

 

[Andrew_xxx]

Thanks. The balustrade fitters say 10cm deep into brick with a resin and rod using the side fixing is acceptable.

 

[SammyInnit]

Thanks. The balustrade fitters say 10cm deep into brick with a resin and rod using the side fixing is acceptable.

Let's hope the mortar bed is up to it. I am very sceptical as to why I asked if it was an after thought and if there was concrete behind or soil. I'm sure it'll work out.

 

[Andrew_xxx]

Sammy, thanks for all your thoughts on this.
I really do share your concerns about the ability of my masonry to take the weight of the glass and the posts as there is going to be an awful lot of weight to bear.
I have listened to the fitters, but as it is my balustrade! and you only get one chance to get this right, I am going to remove the paving, hack out the mortar bed, take out about 6 inches wide and deep of the packed aggregate, and then refill with 6x6 inches of concrete, then re-lay the slabs on mortar on top of the concrete.
This should then give an adequate bed to put a resin fixing into, vertically through the slab.
Agree? Or would you put a deeper layer of concrete?

 

[^woody^]

You don't need a resin fixing - that's a solution to other problems.

And it's not the weight of the ballustrade that is an issue, but the wind load which will rock the ballustrade and the wall it is fixed to. Apart from the obvious gusts, the bigger issue is the gradual small to and forth swaying which acts on the wall and typically cracks the joints.

So you never want to have small groups of fixings in the top few course of a wall. Your concrete plan behind the wall won't help, and will do nothing really.

 

[Andrew_xxx]

Hi thanks, I'm not sure you understood what I mean. I won't be putting the fixings into the brick. I'll be putting them into the concrete. Surely that will help?

 

[^woody^]

Isn't the ballustrade being fixed to the wall?

 

[Andrew_xxx]

Originally this was the plan yes, but I agree with all the advice on here that the brick is not going to provide a strong enough structure.
So plan b is to sit the balustrade posts on top of the slabs and fix vertically through the slab. If I add concrete underneath I can avoid having to fix into brick. It is going to have to sit slightly further away from the edge than I would like ideally, but going into a concrete base rather than the brick is I'm sure the right thing to do.