In the mortar or in the brick ?

[COOPES]

Hi Forum

I want to attach some woodwork and other items to my outside brick wall.

The bricks are nasty artistic stuff with lots of diamond hard clinker like inclusions - first attemt with a hammer drill made little impression. This may be the bricks or my choice of tools. .ANND these bricks of mine also have 3 internal holes that run verticaly when laid.

I see other similar walls on other sites with dynabolts being inserted through the mortar - between the bricks to make connections. On one Dynabolt attempt the mortar disintergrated so no anchor --- should I replace mortar with something else - get a bigger dynabolt -- have seen some sort of adhesivre being used.

In short what are the options when attaching.

Help !

Cheers COOPES

[journeyman Mick]

Coopes,
generally fixings are made to the bricks rather than the mortar. In your case this may be more difficult than usual. If you use a proper hammer drill (ie a rotary hammer drill where the bit floats in the chuck and is actually driven forward with hammer like blows) with a good quality bit you will have more success at getting a good clean hole where you want it. You may need to work out where the hollow cores are and try to avoid them if possible. If you need to fix anything substantial you will need to use a chemical anchor system. Both Hilti and Ramset (and probably others) make systems for use in this type of application. You drill a hole and insert a hollow mesh sleeve of plastic or metal mesh (depending on strength required). Then you inject a two part glue and insert your fastener. Once cured you can attach the load to the fastener. The glues come in special cartridges, some able to be fitted to a standard caulking gun, others use proprietry systems pruduced by the different manufacturers. These glues aren't cheap and tend not to have a good shelf life when opened (even if refrigerated). It may pay to take a sample of your brick to either of the above suppliers to get further information and get them to give you a rundown on your options as I haven't seen an up to date catalogue for a few years now.

Mick

[bitingmidge]

Coopes,

I can't add anything to Mick's advice re drilling/fixing. All good stuff.

There is another trap for young players here though, depending on the use that you intend to make of the timber plate and the method of the construction of the brickwork:

In a typical brick veneer construction, brick ties are a deformed strap metal device, which are susceptible to rust and if the brickie has used a bit less cement on the day he built the wall - to pulling out of the mortar.

I have seen a few instances where verandahs have beeh slung off the brick skin, and without bracing have actually pulled the brickskin away from the wall, fortunately in my personal experience it only took money to fix.

In a tragic incident some years ago, a hammock was fixed between a brick skin and a verandah post. Small child jumped into hammock bringing down brick "wall" and died.

If there is any risk I always tie the new structure through to the structural frame, and treat the brickwork for what it is:- a veneer skin. (same applies for cavity "full" brick) by the way.

As far as the size of bolts go, engineers always specify sizes about three times bigger than what I reckon, so go at least twice as big as you think, and double the number of fixings!!:D :D :D

Hope this is of some use,

P

[GeoffW]

Coopes

May seem like an obvious question but were you using a good quality masonry (tungsten tipped) bit? Otherwise I can't see why you would have a problem.

Otherwise I can't really add anything else to the other advice so far.

Geoff

[MrFixIt]

Hi Coopes


Originally posted by COOPES

The bricks are nasty artistic stuff with lots of diamond hard clinker like inclusions - first attemt with a hammer drill made little impression.

That is to be expected as clinker like bricks are usually the result of being next to the heat source in the brick kiln. The nett result of this is VERY HARD bricks.


This may be the bricks or my choice of tools.


So though you may be using quality tools, it will still be hard to drill. It can be done but it may take more effort than you think worthwhile :-) .ANND these bricks of mine also have 3 internal holes that run verticaly when laid.



I see other similar walls on other sites with dynabolts being inserted through the mortar - between the bricks to make connections. On one Dynabolt attempt the mortar disintergrated so no anchor --- should I replace mortar with something else - get a bigger dynabolt -- have seen some sort of adhesivre being used.

In short what are the options when attaching.

Help !

Cheers COOPES

Well, this is a how long is a piece of string question :-) There are many variables. As you have found out the quality of the mortar is one. The amount betwen the bicks is another. How heavy the items are that you wish to hang and how many fasteners are needed.

The best place to install wall anchors is actually between the bricks. The effort needed by the anchor to push the bricks apart is much greater than that needed to crack a brick. However in both cases the holding power is fairly high.

I would contemplate inserting 6mm rawlpug fasteners almost anywhere within a wall. However 10mm or larger you need to be careful. It is preferable to insert the Loxin or Dynabolt in the VERTICAL mortar joints rather than the horizontal joint. However a row of such fasteners in a row close to the edge of a wall can EASILY split that joint. Use care when placing several fasteners in a line.

ps Don't replace the mortar with new mortar (or something else) and then attempt to use it as am anchor point. Completely unsafe.

If you want to provide more info perhaps we could odffer more advice/suggestions.

Regards

Peter

[bitingmidge]

It is preferable to insert the Loxin or Dynabolt in the VERTICAL mortar joints rather than the horizontal joint.

Whoa!!! Sorry Mr Fixit, but I beg to differ! It may be preferable BUT only if the perpends (verticle joints) have been PROPERLY AND SOLIDLY filled.

Many, perhaps the majority of bricklayers take the lazy way out when laying bricks and only butter the back and front face of the perpends. This gives them an air space and makes it easier to move the brick into its final position.

Air spaces and dynabolts are not traditionally compatible!

Don't even contemplate a rawlplug if you are supporting a structural member.

"Coopes, what are you building exactly by the way?"

cheers,

P

[COOPES]

Thanks to all above for the advice.

P - It's an on going problem with these walls and this is what I want to install or fix -

1. Light wooden trellis.

2. An angle brackets to support a hanging flower baskets.

3. REPAIR to hold the working part of a "pull out" cloths line where the Dynabolt has worked lose in the horizontal mortar course.

4. Possibly attach a sail cloth for shade (but now thinking of that wall coming down)

And Peter what is the danger of refilling the joint with say sand and cement.

***

Talking about drills - is there a difference between an impact drill and a hammer drill - is there another action? Is the floating head a different action or a better product. Also speed - I notice that my old Black & Decker dual speed hammer drill has a speed tag 900/2400 but a new Makita Rotary Hammer ($800) has a variable speed of 360 - 720 (much lower) so drill speed is something I need to know.

Thanks

Cheers COOPES

[Barry_White]

Hi Coopes

All of what Journeyman Mick says is correct but I would add the following.

The best drill is a Rotary Hammer Drill like a Ramset or a Hilti and this you should be able to hire from a hire place rather than buying one unless you intend to do copious amounts of drilling in hard bricks.

It doesn't matter how hard the bricks are these drills will drill them. In fact the harder they are the better they will drill them with only light pressure on the drill.

Rather than using Dynabolts especially in bricks with holes in them I would use Ramset Delta Nylon Plugs.

How do I know this. I spent 10 years installing shop fronts and windows in multi storey buildings. 5 years installing rollers doors (12mm Nylon Plugs will support a 3metre x 3metre roller on brickwork without any trouble at all, so what you want to install will be a piece of cake.

Apart from that I also spent 2 years as a Ramset Rep. so I do know what I am talking about.

[MrFixIt]

Originally posted by COOPES
Thanks to all above for the advice.

4. Possibly attach a sail cloth for shade (but now thinking of that wall coming down)

And Peter what is the danger of refilling the joint with say sand and cement.



Hi Coopes

There is no danger of refilling the joint with new mortar. The danger could be if you try to use this "new" mortar for some "heavy duty" fixing or load.

Re the shade cloth fixing. Keep in mind that there is a substantial load within the cable just to support the sail. This load is increased during windy weather

Regards

Peter

[silentC]

I used to install Tilta-doors and we found that the best way was to run a long coach bolt all the way through between the bricks in the vertical join. Only really useful for single brick walls though.

Couldn't you use some kind of toggle bolt that drops down behind the back of the brick inside the cavity and that way doesn't rely on the mortar at all? They make many different styles and I'll bet you could find one that would work.

Dynabolts, Loxins et. al. work by expanding which is always going to be a problem in soft mortar.

[MrFixIt]

Hi All


Originally posted by silentC
Dynabolts, Loxins et. al. work by expanding which is always going to be a problem in soft mortar.

Sorry for the long reply :-)

One of the reasons (I mentioned in a previous message) of using the perps (vertical joints in brick work), is because the person attaching "things" to a wall does not know the quality of the mortar.

However, it needs to be remembered that expanding bolts such as dynabolts and MY PREFERED type, Loxins, expand (theoretically at least) in all directions. So the use of such fastener types are (within reason) independent of the mortar quality. In other words they are not (so) dependant on the mortar quality for their holding power.

The pressure exerted _BETWEEN_ the bricks give them their holding power. This is why I mentioend in another message (somewhere) that they cannot safely be used in the same horizontal (vertical) row if that row is near an edge of a wall where that edge is unsupported (by some other construction/heavy/immoveable object).

In essence then, Loxins and to a lesser extent Dynabolts are not dependant on the quality or quantity of the mortar in the joint. They rely on the overall wall structure/strength. Loxins and Dynabolts are in effect trying to push the bricks (concrete etc) apart and DO NOT rely on the surrounding grip for holding power. They do of course need to grip the surrounding material to prevent rotation, however once the presure is exerted (in a brick wall) between the bricks the quality/quantity of mortar is less important.

For shear holding power the Loxin is hard to beat. The force that is exerted between the bricks (or concrete) is ENORMOUS. Hence the ability to split walls if placed too close in a single (vertical / hoizontal) joint. Also by design the Loxin has the whole body of the "gripping" source as an integral body. This means that the body is gripped along its full length. Dynabolts by design do not always have this. As the Dynabolt increases in length, the "tube" surrounding the bolt is manufactured in two pieces. This has the advantage of being able to be manufactured in longer sizes, however the (lower) part that grips the surrounding material could be in air space or have insufficient grip at the fixing depth.

Rawlplugs DO on the other hand rely moreso on the surrounding material for grip. In soft mortar this can be a problem.

Kind regards

Peter

[MrFixIt]

Originally posted by bitingmidge
Whoa!!! Sorry Mr Fixit, but I beg to differ! It may be preferable BUT only if the perpends (verticle joints) have been PROPERLY AND SOLIDLY filled.


Hi P

That's ok :-) Feel free to differ.

However it must be noted that Loxins and Dynabolts DO NOT rely on the surrounding material and rotational grip for their HOLDING power.

Certainly there must be some initial "grip" surrounding the fixing. However once the Loxin has sufficient grip to prevent itself from rotating then the HOLDING power is no longer in a rotational direction but is exerted in all directions _perpendicular to_ the axis of the Loxin. In other words, providing there is some immovable object ie brick on either side of the Loxin, once the initial grip is made, you could remove all the mortar surrounding the Loxin and providing the wall is strong enough continue to tighten the Loxin to improve its gripping force.

We could say that the mortar is really only a means of aligning the Loxin, as once the Loxin has a hold of "the bricks" it won't pull out.

Consider the Loxin (Dynabolt) as a wedge. This IS precisely what they are, only a round wedge :-)

(the following is plagiarised from another message of mine)...

However, it needs to be remembered that expanding bolts such as dynabolts and MY PREFERED type, Loxins, expand (theoretically at least) in all directions. So the use of such fastener types are (within reason) independent of the mortar quality. In other words they are not (so) dependant on the mortar quality for their holding power.



Many, perhaps the majority of bricklayers take the lazy way out when laying bricks and only butter the back and front face of the perpends. This gives them an air space and makes it easier to move the brick into its final position.


If you consider my message above you will see that this air space is not a problem with Loxins, as long as there is suffiecient mortar at the Loxin entry point to prevent it rotating as the initial grip is obtained, ie to prevent it from rotating, you can obtain full strength WITHIN the AIR SPACE providing the bricks either side of the Loxin cannot move.

IN FACT you can even get a Loxin to grip in very loose surroundings (again within reason).

You can FORCE the initial grip of a Loxin. Using a length of threaded road, screw a nut on to the threaded rod, far enough to allow the same end to be screwed into the nut of the Loxin. Now screw the threaded rod into the Loxin nut, grip the threaded rod and tighten the nut down on the Loxin. Continued tightening of this nut will cause this to expand the Loxin body and obtain some grip. Now you can unscrew the nut and threaded rod and carefully insert the required bolt and tighten, VOILA!

After this trick, don't push too hard on the bolt after inserting it, as you may loose this initial grip and need to start over.



Air spaces and dynabolts are not traditionally compatible!


This is certainly more applicable to Dynabolts. However with care they can in most cases still be coerced into gaining the required grip. As with Loxins (though not as well), once the grip (perpendicular to the Dynabolt axis) has taken hold, then the grip will continue to improve.

The difficulty present with Dynabolts is when they have multiple "tubes" surrounding the bolt. If such a long bolt was in "air space" then sure, the is little that you can do.

In such circumstances though you would most likely find that a Loxin and allthread may do the job.

Kind regards

Peter (the Loxin's friend :-))

[silentC]

Despite all that, they have been known to fall out, haven't they? ;)

Take a loxin for example. Suppose it is the same diameter as the mortar join. When expanded, it will contact with the brick on either side. However, what is above and below? Mortar! So if the sideways pressure is not enough to prevent the fastener from moving vertically, eventually it can work lose. You're going to say "not if they are installed properly". That may be true but is it always possible to get an optimal arrangement of the loxin's body in relation to the bricks on either side? Are the two bricks always parallel? Are all bricks as hard as each other?

Imagine you have a sun sail attached to one of these. The wind gets under it and whips it upwards, pulling on the fastener in an upwards direction. Then the sail whips back down again, the stress on the fastener is in the opposite direction. This is effectively wriggling the thing up and down, with the bricks on either side forming a pivot point. Eventually it may work itself lose.

This is exactly what happens with a Tiltadoor and is why we stopped using Loxins to fix them to the walls.

With a toggle bolt, even if it does work itself loose, it wont come out.

:)

[soundman]

All this discussion.
It needs to be reinforced that most exterior brickwork can not be considered structrual.

Further the australian standard on TV antenna installation states that fixings shall not be made closer than 4 courses from the top of a wall.

I have seen bricks pulled out of walls and various fixings pull out.

I personaly would not make any substantial fixing to the mortar of any brickwork.

If you can bust a brick with the fastener you are expecting too much of the brick.

for the light loads such as a bit of trellis & the like, even tap-ins (nylon nail in anchors) would do the job.

The argument about the various benefits heavier types types of masonry fixing it totaly spurious if we are talking about brick work.
No engineer would sign off against any method.

A further thaught.
in the past I have replaced TV antenna "J" brackets that have been fitted to the mortar with 2 x 10 mmx 40mm dyna bolts.
removal method
grasp with two hands riggle like buggery and pull. Almost always comes out.
Same bracket new dyna's the same into the middle of two seperate bricks. Never seen a failure.
A TV "J" bracket is a light load.

Easy enough to test if you are keen!!!

[silvia]

Hiya Barry *waving* I work at Ramset as well and hopefully can shed some light on several of the issues here for you guys.

Construction always recommends brick fixing over mortar fixing becuase brick strength can be measured, while mortar strength is widely varied.

Standard brick strength for a brick in WA is about 300kg before breakage and pullout.

1. Fixing light wooden trellis. Use a nylon knock-in anchor with a stainless steel pin, or a small ramplug with the appropriate sized Class 3 (grey) screw. This will work anywhere on the brick or in a pinch in the mortar (keep the above comment in mind though).

2. Angle bracket. Wet plant pots get heavy and the leverage on the anchor means you need to be a bit more circumspect about what you choose to fix with. If it is less than 40kg overall then a Mungo or long Ramplug is a good choice into the brick. Use a galvanised coach bolt and a plug at least 10mm x 80mm long.

3. Repair. Clothes lines exert a lot of tension, and there is a deal of vibration as well in normal use. A chemical anchor is recommended here for a permanent fix as it will never slip or move again. Fix nearby straight into the brick.

4. Sail shade. Same as number three, but check the maximum pressure that will be exerted (ie by strong gusts). Fixing deep into double brick chemically is a winner.

_________


Okay.. drills.

I can get right into this, but basically the more you are paying the more likely it is that the drill will get your job done faster. Small holes = small drill and big holes = big drill. For work mainly 5 - 12mm the best is a 2kg hammer and for 10-20mm the best is a 4kg hammer.

For this specific job go out and hire yourself a 4kg hammer drill (preferably Ramset!) and the right size carbide drill bit. If you are used to a vibration drill (typified by their high whiney note in use) then remember not to lean on an air hammer as its all in the blow. If you lean you smother the blow force.

Rotary speed is directly related to the size of hole it is suited to. If you look at the specs you will see that the impact force (Joules) will go up as the rotary speed and impact rate goes down. This suits big holes best.

_____

In regards to Loxins and Dynabolts - officially neither are recommended for use in either hollow brick or in mortar. However we have plenty of customers who swear by both! Commensense rules here and if its a little load then it won't be an issue but if you have a biggie then it pays to be a little more thoughtful with your choice of fixing.

sil

[soundman]

Just as a matter of interest bunnings have the $100 rotary hammer back in stock again.
A bargin in anyones terms.
I baught one & so did a couple of builder mates.
The seem to work well & come with 3 sds bits and a chisel.
To complete the package , go to trade tools & grab their cheep sds bit set. A fist full of sds drill bits in 3 lengths and 4 chisels for about $50 bucks.

neithe will stand up to the pounding like a hilti or such but for the ocasional user beats grinding away with an ordinary hammer drill.

O btw general comment about ramset drills.
If they used a standard sds bit more people might buy them.
I wouldn't touch one with a barge pole while they persist with a proprietary bit system.

[silvia]

You're absolutely right - more people would use the Ramset drills if they used a generic SDS bit.

And in fact the smallest drill in the range, DD520 2kg hammer will take a generic SDS bit to cater for the small users looking for economy.

However the R3 bit was designed for the industrial user, with reliability and speed a priority. It is extremely fast and long lasting. The key design triples the chuck life of the Ramset tool. Subbies simply can't in any fashion jam the chuck with a SDS bit put in backwards. That all saves the tool owner time and money from less problems and breakdowns on site - at $40 an hour you want to go as fast as you can with no delays.

It is also to my knowledge the only Australian based multifit bit patent on the market =)