Zone 2 dish on rendered wall

[paulw]

This is my first foray into mounting a satellite dish which will be
non-motorised.

I'm going to mount a Zone 2 dish on a rendered external wall
for a friend. I believe the render is about 2 cm thick (does that
sound about right?). To attach the bracket to the rendered wall
I intend using 4 x 8mm sleeve anchor bolts that are 65 mm in
length. Would these do the job? Any other hints, do's/dont's,
for attaching mounting brackets to rendered walls?

Is it OK to hammer (gently or otherwise) the bolt sleeves
into the drilled holes?

Also, how important is it that the bracket is bolted absolutely
square to the wall and any tips on how to ensure that this
can be achieved -- to a certain extent, one seems to be at the
mercy of where the drill decides to bite.

I'll be using an SDS drill to drill the 14mm holes needed to take
the bolt sleeves.

Thanks in advance for any advice.

Regards,
paulw

[TheBadger]

You can get the drill to bite where you want by indenting the render with a punch first. As you don't know where you will hit the substrate (brick, block, etc.) I would be tempted to use MultiMontis or something similar which doesn't expand in the hole and could cause integrity problems.

[AJR]

Hi paulw

Be a bit cautious and the render should be fine

Drill a pilot hole first using a smaller masonry bit (6mm ish) & don't use hammer action

Are you sure you need to use fixings that require a 14mm hole (its only a zone 2 dish)


absolutely square or as near as dam it can be achieved with a spirit level :)

[paulw]

The fixing bolts are 8 mm but the sleeve, into which the
bolt screws, requires a 14 mm hole. I practiced this by
drilling into a spare brick but even at 14 mm I couldn't
get the sleeve completely into the hole -- mind my
drilling wasn't exactly brilliant, hence the question
about whacking it home with a hammer.

Is it generally a good idea to build up the drill bit diameters,
say, 6, 10, 14, rather than go straight in with a 14mm drill bit?


@TheBadger
I'll check out the Multi Montis -- hadn't heard of them.
The fixing bolt is going to be partly in render and, I
believe, partly in brick. I'll invest in a punch too.

@AJR
Thanks for the advice on drilling a pilot hole first.
That should also help find out exactly what is below
the render.


Regards,
paulw

[AJR]

The fixing bolt is going to be partly in render and, I
believe, partly in brick

Noooooooooooooooooooooooooooooooo ooooooooooooooooooo..

The fixings must be pushed below the level of the render, other wise the odds are 98 to 1 that the render will crack..

Multi Montis are very very good, but expensive.

I would recommend the 10mm plastic 'rawlplug' style of fixing' with screw in bolts, like shown here...


http://www.grax.co.uk/P/Mungo-Fixing-nylon-bolt-complete(82).aspx

[AM556]

A rawlbolt of 65mm is perfect mate, 15mm for the render and 50mm into the brick. The expansion part is then 2" into brick and won't harm the render.
Drill your holes, with pilot if required. Assemble the rawlbolts onto the wall bracket but don't tighten them or they will start to expand without you realising it! Offer the assembly to the wall and offer the rawlbolts to the holes then tap evenly with a hammer 'til the bracket is flush with the wall (uneven or not) and tighten solid. Then and only then, slacken the bolts part way and pack with washers behind the bracket as close to the bolts as possible IF you need to square the assembly.

[paulw]

Assemble the rawlbolts onto the wall bracket but don't tighten them or they will start to expand without you realising it!

Hmm! When I first bought the anchor bolts I took them out of the packet
and unscrewed them from the sleeve and then screwed them back in fully!
If they expanded, then that could be one reason why I had trouble trying to
push the sleeve into the test holes I drilled in the spare brick. Does this mean that I should discard these bolts? I got them from B&Q?

Well, there's a few options to ponder here. I'll be setting the dish up in
the New Year, so plenty of time to decide what to do.

Thanks for all your input. Much appreciated.

Regards,
paulw

[AM556]

There are many types of "expansion" bolts, by the dimensions you gave, I'd guess they are Rawlbolts, Dynabolts are slimmer so your hole would have been 10/12mm. A rawlbolt has 4 expanding legs with a nut at the far end which is drawn toward you as you tighten. If you have a Rawlbolt, there is a wire ring that retains the legs and as long as it still holds the legs, your ok to re-use mate.
All expansion bolts must be a snug fit in the hole or else it will turn in the hole as you tighten (not good).

[paulw]

@AM556
Your rawlbolt description matches the bolts that I have to a tee.
B&Q mark them as anchor bolts. The retaining wire is in place, so
it looks like the bolts are OK to use.

Regards,
paulw

[AM556]

Yet another tip for you.
Don't be tempted to remove the bolt once tight, slacken, yes but don't remove all the way. Otherwise you'll find it a beech to get back in with all the dust in the hole, it can cross thread or even push the nut too far into the hole :frown: then you're in deep doodoo.

[AJR]

And also ...

If using washers for packing or even as washers :302:

Steel rusts and rust stains on a rendered wall looks bad so use non rusting ones.