anchoring in brick/plaster for stair brackets

[mrFinpgh]

The brackets currently on the stair railing are loose in the wall.  I think the tapcons weren't well installed and the brick might have cracked from the holes being so close.

I want to replace the brackets with some new ones so I've been going about gathering materials.  Instead of tapcons, I'm going to use some heavier duty anchors (Fischer duopower) with 2.5" #10 screws. 

The anchors themselves are only about 1.5" long. What I was thinking about was this: if I put some wood deeper in the hole, behind the anchors, then can the screw also bite into that and thus be more securely embedded?  Or would this be relatively meaningless and only add further complications?

 

[Koamolly]

Epoxy.

 

[AlexThePalex]

The anchors themselves are only about 1.5" long. What I was thinking about was this: if I put some wood deeper in the hole, behind the anchors, then can the screw also bite into that and thus be more securely embedded?  Or would this be relatively meaningless and only add further complications?

Why not get longer anchors?

First the surface in which you screw into has to be secure. So fill all holes in the wall with cement, or an epoxy if they're small. Then drill a hole in there for the anchors, which should be matched in size to the screws you use. You should not use a 1.5'' anchor with a 2.5 inch screw, but make both 2.5''.

 

[RKA]

I don't understand how you would put wood in the hole in a way that would allow a secure installation.  It all depends on the substrate you are anchoring into, the condition of that material (it was previously drilled out and some of it has crumbled? and you have holes in close proximity to one another).  Without a clear understanding it's hard to recommend something. 

If the holes are intact (no cracks or missing material) and the screws are just loose, you can clean the hole to remove any loose debris, drop some pieces of insulated stranded wire in the hole and run your screws back into the wall.  That will likely tighten things up and it will hold for a very long time.  This may be what you were suggesting with the wood above, but coated wire will do a better job.

 

[mrFinpgh]

Thanks, all.  I appreciate the feedback.

To clarify, I am planning on drilling new holes and patching the old ones.

In the past, when I've had a hole that was just a little loose for an anchor or a screw, a couple pieces of veneer seemed to lock everything down quite well. 

In this instance, what I was thinking about was a piece of dowel pushed in behind an anchor to just provide something additional to bite into with the screw. Maybe that's not a great idea, though.

To Alex's point, I'd rather use 2.5" anchors, but I have not found anything in that length besides really heavy duty metal anchors, which I think would be perhaps a bit overkill for this case. 

I did think about epoxy, but I think I would have the problem of trying to inject epoxy a couple inches in a 5/16" hole.. not sure how I would pull that off.

It sounds like folks are skeptical of the wood plugs solution, so I'll take another look to see if I can find longer anchors but my last efforts didn't return much.

 

[DeformedTree]

From your post, is there wood behind the brick?  If you can completely pass thru the brick into wood (with probably epoxy or such in the hole for support), that would probably be a better option.  The railing is going to flex the anchors over and over and just turn the brick around the threads to dust over time and you are back at this again.  It's a safety system and trusting just a few small tapcons would not be my first choice.

Within the brick, I might suggest going for some sort of stud with epoxy, or a threaded anchor/insert.

What kind of brick is this, is it thin brick, or structural.  Solid ones or hollow?  Newer harder stuff or old one that flake just being touched?  If it's a just a course of face brick, how well is it attached and to what? face brick walls tend to flex and not be anchored well, thus my comment about going to wood if that is back behind the brick.

 

[mrFinpgh]

It's an old brick rowhouse with plaster walls over brick on the exterior, plaster+lath on the interior. So, it's structural brick.  This happens to be the brick firewall between the adjoining house.  Definitely no wood behind it.

From my previous experiences on this hosue, it's sturdy brick - not crumbly at all but not the extremely hard brick used around the fireplace.  An SDS drill can get through it easily but a regular hammer drill takes a while.

 

[DeformedTree]

Ok,  so yeah, sounds like a good solid wall.  Anything where you can epoxy something in still may be best, threaded stuff in brick has a tendency to want to strip out just as it starts to clamp down.

 

[mrFinpgh]

Ok, now I have more questions.  [laughing]

What kind of epoxy would I be using for that?  And what kind of hardware? 

The brackets I've got use #10 or #12 screws - would I be able to epoxy those in the brick?  Or am I epoxying the anchor into the brick?  If I put epoxy around the anchor, does that make it more likely to shatter the brick?

 

[AlexThePalex]

In this instance, what I was thinking about was a piece of dowel pushed in behind an anchor to just provide something additional to bite into with the screw. Maybe that's not a great idea, though.

Indeed, it is not.

To Alex's point, I'd rather use 2.5" anchors, but I have not found anything in that length besides really heavy duty metal anchors, which I think would be perhaps a bit overkill for this case. 

You mentioned Fischer plugs, of course I can't say anything about availability in your area, but over here they come in a whole lot of varied sizes. I always have some long ones at hand. These are 60 mm and will provide proper support for your stair railing.

[attachimg=1]

I did think about epoxy, but I think I would have the problem of trying to inject epoxy a couple inches in a 5/16" hole.. not sure how I would pull that off.

With your freshly drilled holes you don't need epoxy. Forget about epoxy, getting the right plugs is the proper solution. I only mentioned epoxy in case you have to fill an old worn out hole. But manufacturers are way ahead of you with epoxy for screw holes if needed, they have their own injection methods, look up "chemical anchor".

DeformedTree mentions plugs have a tendency to come loose, that's only true if you use plugs that are too small for the load they have to carry. Using 1.5'' plugs on a stair railing might fail, they might not, but using the 60 mm ones I show will definitely not.

 

[Bob D.]

What about using a 3/8" Hilti drop-in anchor. Set it down deep (not flush with surface), about a 1/2" below the surface for a better bite. If you set it flush with the brick face it might spall and loosen over time. But I would be worried about that with anything secured into brick which is much softer than block or concrete. You'll need a 1/2" hole for a 3/8 HDI Anchor.

They are also available in SS if you are worried about exposure to the elements.

I have used Hilti HIT-RE 500 Epoxy Adhesive to secure many anchors on jobs, even underwater. It holds up well. Out of over 200 installed on one job in 2011 we never had one fail. These were installed underwater to anchor large multistage centrifugal pump supports to concrete walls. We used 316L SS anchor rods as this was salt water which will eat just about anything except Monel 500 and other super stainless steels.

Hilti also makes a capsule adhesive anchor system. You drill the hole and insert the adhesive pack in the hole, then drive you anchor rod in. No muss, no fuss. It's certified for seismic applications (in the right base material). Five minutes from installation to loading, doesn't get much faster than that.

 

[DeformedTree]

Something like what Bob shows is what I'm thinking.  My main concern is it's a hand rail, so people will be yanking on it, and when the day comes that it's going to save someone you don't want it to yank out.  The screws you had mentioned are just very short.  Ignoring brick, if this was the bracket for a hand rail on a wood wall, you would hold them in with something like 3" screws into studs, so I would want something to be as strong in brick.

I just don't trust brick to give a consistent and known hold, one hole could be fine, the next fail.

 

[AlexThePalex]

I just don't trust brick to give a consistent and known hold, one hole could be fine, the next fail.

[blink] What kind of quality of bricks do you have over there? Apart from concrete it's the strongest building material available for houses.

Over here everything is made out of bricks or concrete, you can hang so much on a screw hole if you make it right.

Those chemical anchors Bob shows are total overkill for a hand railing.

 

[Jiggy Joiner]

Chem-fix did systems similar to the Hilti ones Bob posted. We used them for bolting posts etc to concrete. You’d drill a hole in the concrete, and then insert what looked like a test tube full of two part epoxy, then tap the studding/bolt in which broke the glass seal, allowing air to activate the epoxy.
We’d leave the studding/bolts in for a while to set, then fit washers and nuts, and tighten them down. This was, and still is an incredibly strong way to anchor things into concrete and brickwork, probably overkill for a handrail.

Much of the time now, when fixing into brick and concrete, we use concrete screws. You drill a hole in the brick, and screw the concrete screw straight in, no plugs etc. Very strong method, depending on the strength of the brickwork itself. These screws come in all sizes and would certainly hold a handrail securely.

 

[mrFinpgh]

Lots of feedback and ideas here.  Much appreciated.

[member=5277]Alex[/member] what I've found is it's very hard to get that length of plastic/nylon anchor in the US.  They seem to max out around 1.5" and then it's mostly bolts and heavier gear.  It looks like Europe has a lot more options in this regard.

[member=68063]DeformedTree[/member] [member=60461]Bob D.[/member]
For the brackets I'm using, I think a 3/8 anchor would be impossible to accommodate.  These aren't built for heavy duty, and I'm adding an addition 2 brackets over the length of the rail to help distribute the work.  I agree that sometimes the tapcons don't always do a great job.  My experience has been that it's typically due to hitting the edge of the brick or the mortar, so the hole crumbles a bit more and it doesn't stay tight.  Where the hole is all brick, it's never been a problem in this house.

[member=69479]Jiggy Joiner[/member] I originally was thinking of tapcons/concrete screws, but I ran into the issue of the blue or white heads looking pretty terrible against the black bracket.  With the wood screws, I was able to blacken them with gun bluing solution so they are much closer in color.  I don't think I could do that with the coating they put on tapcons. 

I did look a little bit and it looks like they do have some black plastic screw covers that might do the trick if I went that direction - little hinged things that would snap over the screw and at least keep the contrast down.

 

[Michael Kellough]

Plastic anchors for #10, 2” long, for 1/4” hole at McMaster.com

Search screw anchor. These look like headless sleeves.

 

[DeformedTree]

I just don't trust brick to give a consistent and known hold, one hole could be fine, the next fail.

[blink] What kind of quality of bricks do you have over there? Apart from concrete it's the strongest building material available for houses.

Over here everything is made out of bricks or concrete, you can hang so much on a screw hole if you make it right.

So I think the answer is our bricks our a good bit different.  True brick construction ended probably 100 years ago here.  It's all face brick now.  Build a concrete block wall or poured wall and put a course of face brick in front of it (cosmetic),or face brick in front of wood frame construction.  Older bricks, even into mid century are not very durable. Stuff has to be regularly rebuilt and you can general pull the stuff apart by hand, just small taps snaps the bricks. New bricks are much better, but again they are rarely used in load bearing situations, the structure holds them up. Solid new brick are vastly stronger than old stuff and probably will hold screws well, but they still are nothing compared to concrete.  I would think it would be similar over there.  When repairing houses from mid century and back you have to use soft mortars or the mortar will break the brick.

I would think the basic common bricks here and where you are would spec wise be similar, but I just don't know. But again structural brick construction is basically dead here. Bricks are made for their looks, not structure.  From what I have seen of what is over in Europe, your bricks look to be much stronger/durable product than what is here.  Maybe someone with experience in Europe and N.A. can chime in.

 

[mrFinpgh]

So I think the answer is our bricks our a good bit different.  True brick construction ended probably 100 years ago here.  It's all face brick now. 

My house is about 90 years old, which might explain the sheer quantity of brick

 

[DeformedTree]

So I think the answer is our bricks our a good bit different.  True brick construction ended probably 100 years ago here.  It's all face brick now. 

My house is about 90 years old, which might explain the sheer quantity of brick

They got a discount at a fire sale.  But yeah, sounds about right.  If it's a row house, it would be one of the last thing built full brick.  Within a few years you have WWII and basically brick construction never came back after the war.  I'm sure there were people someplace doing them, just like people who will still build foundations out of concrete block today, but just became very un-common.

 

[demographic]

I've put handrails down nursing home stairwells that were dot and dabbed plaster board over concrete block walls before.
I added 4x1 timbers over the dot and dab walls with chamferred corners to fix the metal  handrail brackets onto.
This meant I could fix the metal brackets onto something that wouldnt wobble when elderly patients put a bit of weight on them.
The 4x1 timber was fixed to the wall with 3"screws and panel adhesive.

Just fixing the handrail brackets through the plasterboard would have meant they could wobble and dent the plasterboard in in my opinion.

One of the situations where I had to argue my case to the main contractor who just wanted it done fast and cheap but I didn't feel it was safe so wanted sokething a heavy person could rely on more.
Think it was up six flights of stairs and around every corner of the half landings as well so it took a bit of time.