Anchoring Concrete Or Anchoring Epoxy ?

jalapeno · August 21, 2013

Need to set rebar in pre drilled hole in brick wall .

Know where I can get Anchoring cement or Anchoring epoxy ?

I am told that regular concrete or cement based mortar shrinks when it sets so the rebar will be loose in the hole.

Will try FINCO in Kolupitiya tomorrow. Was wondering of other specialist concrete or anchor systems retailers?

Know about Hilti and will try them too, I know they have chemical anchors/adhesives for anchor bolts and steel rod .

Edited August 21, 2013 by jalapeno

VVTi · August 21, 2013

I had several points in our house anchored using HILTI chemical anchors. Hunter's in Nawala Road near the OUSL has the stuff. You will need to drill the holes where you want them and tell them the size of the hole (Diameter, depth and the number of holes). they will then give you the required amount of the chemical. Also you will be required to keep a deposit of around 10K for the applicator which you must return with in 24 hours, they charge around 500 per day.

I would not go with any other anchor system. HILTI has worked wonders for us. Expensive though. Each cartridge is around 6500LKR.

Or if its a brick wall like you mentioned, you can put large washers from the flip side and anchor it?

Edited August 21, 2013 by VVTi

SubZero · August 22, 2013

Hilti RE500 is used for anchoring in horizontal concrete surfaces. Hilti has some other chemicals for different circumstances as well. VVTI is correct about the agent and the location. Further, be careful when working with the chemical gun. It is an epoxy and if you do not clean up quickly, it will harden.

But since you mentioned a brick wall, I think you would have to stick to a different method.

Edited August 22, 2013 by SubZero

jalapeno · August 22, 2013

On 8/21/2013 at 6:13 PM, VVTi said:
I had several points in our house anchored using HILTI chemical anchors. Hunter's in Nawala Road near the OUSL has the stuff. You will need to drill the holes where you want them and tell them the size of the hole (Diameter, depth and the number of holes). they will then give you the required amount of the chemical. Also you will be required to keep a deposit of around 10K for the applicator which you must return with in 24 hours, they charge around 500 per day.

I would not go with any other anchor system. HILTI has worked wonders for us. Expensive though. Each cartridge is around 6500LKR.

Or if its a brick wall like you mentioned, you can put large washers from the flip side and anchor it?

On 8/22/2013 at 3:38 AM, SubZero said:
Hilti RE500 is used for anchoring in horizontal concrete surfaces. Hilti has some other chemicals for different circumstances as well. VVTI is correct about the agent and the location. Further, be careful when working with the chemical gun. It is an epoxy and if you do not clean up quickly, it will harden.

But since you mentioned a brick wall, I think you would have to stick to a different method.

The application is attaching anti-climb spikes on top of a brick wall. The spikes are the kind that have a pointed top and another curved pointed bit facing in 1 direction.

Was thinkin of welding rebar rod every 2 or 3 feet to the spike assembly then sticking the rebar into pre-drilled holes in the brick . I will fill the holes with a cement+sand mixture or concrete prior to inserting the rebar.

I was told rebar is not a good candidate for welding. I chose rebar because it has threaded surface so will grip the cement mortar or concrete well. But now I think I'll just go with regular steel rod.

Below picture is like what I am aiming for .Since brick is soft unlike concrete, do I have a problem?

Black = Spike assembly

Red = rebar or steel rod

Green arrows = where the bottom horizontal steel rod that runs the length of the spike assembly will sit (on the wall surface)

Edited August 22, 2013 by jalapeno

VVTi · August 22, 2013

For that I'd say using concrete would be a more cost effective solution. Like Subzero said, Chemical anchors are for horizontal application where effective insertion of concrete is not possible. For this it is a easy job. But I would lay an inch or so of concrete ON the top of the after wards to make it nice and uniform. On that you can sprinkle glass shards to make it that much more unattractive. I am planning on buying concentino wires to secure our back wall and doing a similar job.

Kavvz · August 22, 2013

On 8/22/2013 at 5:08 PM, VVTi said:
For that I'd say using concrete would be a more cost effective solution. Like Subzero said, Chemical anchors are for horizontal application where effective insertion of concrete is not possible. For this it is a easy job. But I would lay an inch or so of concrete ON the top of the after wards to make it nice and uniform. On that you can sprinkle glass shards to make it that much more unattractive. I am planning on buying concentino wires to secure our back wall and doing a similar job.

Have never installed spikes etc on a wall so I can't help there; but you should know that anti-climb bars / pointed spikes actually make it easier to climb the wall. Glass shards on top of a wall don't look as nice, but are a good deterrent. Its much harder to climb a wall with glass shards embedded in it...

Edited August 23, 2013 by Kavvz

jalapeno · August 23, 2013

On 8/22/2013 at 9:18 PM, Kavvz said:
Have never installed spikes etc on a wall so I can't help there; but you should know that anti-climb bars / pointed spikes actually make it easier to climb the wall. Glass shards on top of a wall don't look as nice, but are good deterrent. Its much harder to climb a wall with glass shards embedded in it...

Can't put glass shards, propective tennents and neighbour won't like it.

SubZero · August 23, 2013

Usually rebars are not welded when used in structural purposes. This is due to the change of local composition with the heat. But there are occations when welding is done with additional lap lengths ..etc. But for your purpose welding wont be a problem.

What I feel is you could drill 12mm holes in the brick wall and forcibly insert the rebars. Then after setting up your arrangement, you could put a 75mm thick concrete strip along the wall.(Keep provision for this additional height required when inserting the rebar.) One problem here is since there are no vertical stiffeners, a crack could proprgate along the concrete/ brick joint.

OT but presuming this is a boundary wall, cement blocks would have been a better option over bricks when considering the cost.

VVTi · August 23, 2013

On 8/23/2013 at 12:43 AM, jalapeno said:
Can't put glass shards, propective tennents and neighbour won't like it.

That's a bit disturbing....

jalapeno · August 23, 2013

Hey guys, what do you think of this revised plan?

Instead of rebar and inerting it into deep (10 inch) hole in the brick, I was thinking of welding a steel plate the length of the spike assembly to the bottom of the spikes. Then drilling holes in the steel plate to accept anchor bolts that will be set in the wall.

Black = spike assembly

Solid Red = steel plate welded to bottom of spike assembly

Grey = brick wall

Green dots on brick wall = anchor bolts

Green dots on Red steel plate = hole to accept anchor bolts

----

So anyone think anchor bolts for this application will hold safely in brick?

SubZero · August 23, 2013

Consider the width of the wall. Else the wall will crack and you won’t get proper anchorage.

Guess you are not that worried about the aesthetics.

jalapeno · August 23, 2013

On 8/23/2013 at 6:46 AM, SubZero said:
Consider the width of the wall. Else the wall will crack and you won’t get proper anchorage.
Guess you are not that worried about the aesthetics.

Wall is 10 inches wide/thick . So fi I use 3/8 inch or 1/2 inch steel rod with 1 foot of it below the surface , will it be fine?

Aesthetics is a big deal for me but safety is a greater concern .

jalapeno · August 24, 2013

On 8/21/2013 at 6:13 PM, VVTi said:
I had several points in our house anchored using HILTI chemical anchors. Hunter's in Nawala Road near the OUSL has the stuff. You will need to drill the holes where you want them and tell them the size of the hole (Diameter, depth and the number of holes). they will then give you the required amount of the chemical. Also you will be required to keep a deposit of around 10K for the applicator which you must return with in 24 hours, they charge around 500 per day.
I would not go with any other anchor system. HILTI has worked wonders for us. Expensive though. Each cartridge is around 6500LKR.

Or if its a brick wall like you mentioned, you can put large washers from the flip side and anchor it?

How many holes and what size were they? How many cubic inches will a cartridge give?

I got like 14 holes that will receive 0.5 inch diameter steel bar stock (aka steel shafting) of 10 inches length

So we are looking at a volume of early 2 cubic inches per hole (0.5 inch diameter hole), so 28 cubic inches total but this is for the full volume of the hole . I assume the hole isn't completely filled as the rod being inserted will displace all most all of the chemical anchor?

SubZero · August 26, 2013

On 8/23/2013 at 2:09 PM, jalapeno said:
Wall is 10 inches wide/thick . So fi I use 3/8 inch or 1/2 inch steel rod with 1 foot of it below the surface , will it be fine?
Aesthetics is a big deal for me but safety is a greater concern .

Sorry for the late reply.

If this is for the method I suggested, about 8-10 inches of embedment is enough. But the point is to insert them forcibly. It will be best if you could use12mm (1/2 inch) tor steel rods. When you drill with the same size drill bit, with the rib of the rod, it will go down tight.

If you are going ahead with the second method (i.e with the steel plate) the thread and the nuts of the anchors wil be jutted out. It wont be that neat.

Just a suggestion. You could also consider a chain link fense on top of the existing wall. That is proving to be quite effective these days.

Edited August 26, 2013 by SubZero