My friend, Martin, recently did some plumbing work and sent in the following useful tip and some pics for those of us that are DIY enthusiasts.
Martin suggests ...
A few weeks ago, I was doing some plumbing work on the little ablution block that I was building and I did something that I thought may be of value to some of your readers, so I took pics. There are specialised masonary epoxies available, and although I normally use them, I just didn't have any with me when I did this job. The general purpose stuff worked a treat though.
Quite a few fasteners simply knock into predrilled holes. The problem with some applications is that after a few bumps, knocks or vibration, the fastener works its way loose in the masonry. It's because the two materials in contact with one another have no "give" (in this case, metal in brick). The reason that good quality nylon raw plugs work so well is that the nylon has give, and conforms well to the hole in which it is used and can soak up some knocks.
I have solved the problem very often by partially filling the hole with epoxy adhesive, then coating the fastener with epoxy and then knocking it into the hole. I have never had any of the fasteners work loose and I've been using this method for years.
There is an entire category of "chemical fasteners" used in construction, but very often the method is either not known by DIY folk or else the application equipment is too expensive. Chemical anchors are widely and extremely successfully used in industry.
A word about the epoxy. I have used a general purpose epoxy (slow curing at about 24 hours) but even Pratley or Genkem quick set will work. I use slow curing stuff to give me time.
It's a simple little thing, but something that may assist quite a few DIYers.
The pics in order below:
Pic 1: A good quality 15mm copper pipe holder bat.
Pic 2: Coating the inserted section with epoxy.
Pic 3: Stuffing epoxy into the hole in the brickwork with an old screwdriver. It should be worked into the hole well. Always try and blow out the brickdust from the hole first. I use a short length of flexible tubing so that I don't get a blast of brickdust in my face by blowing directly into the hole.
Pic 4: Fitting the fastener. The hole should be slightly smaller than the fasteners diameter.
Pic 5: There's always a bit of squeeze out. Either let the epoxy set then trim excess off later, or wipe it off while still soft (often a bit messy).
Pic 6: Final product. I did it this way because the exposed pipes in the shower are likely to get knocked often, hence the fasteners will definitely work loose over time.