fixing to old walls

[jimjam]

Does anyone have a good technique for improving the chance of screwing things to old walls.

I'm talking about an internal brick wall, with old lime mortar and a good layer of old lime plaster. If I want to fix something really well, surely I'm going to get a plastic rawlplug well into the brick. The lime normally just doesn't have the strength. But when I drill randomly into the plaster, there's a chance that my drill bit goes between two bricks. Or worse - right on the edge of a brick, so the drill bit moves sideways, making an even bigger useless hole. Another possibility is that the hole is so close to the brick edge, that the brick cracks as the screw tightens.

So what does everyone do? I was wondering if there was anyway to detect the brick locations - like one of those stud detectors.

Thanks.

[dom]

You can try using a very narrow drill to probe for solid brick, but for a really solid fixing I'd forget plugs and use a masonry screw:

[Peter Scott]

don't say what type of brick it is. If very old the bricks might be soft, as they are in my house. You are quite likely to split the brick unless you use just the right size drill and plug, or masonry screws as suggested. Don't use expanding bolts. Use more fixings each carrying a lighter load. Is there anywhere with exposed bricks that won't be seen where you can experiment? If not I like the probe idea.

Peter Scott

[Nightjar]

I had that problem when hanging kitchen wall cabinets. The bracket postitions are fixed and some fell on mortar joints. My solution was to screw a batten to the wall, making sure the fixings for that went into solid brick, then screwed the hanging brackets to the batten. A similar batten near the bottom made sure the cabinets hung square.

Colin Bignell

[The Natural Philosopher]

epoxy mortar or car body filler into oversized hole, THEN insert rawlpug before it sets.

[dom]

To add a bit more detail on masonry screws, you drill at the recommended size, then as the screw is driven home, the hard serrated edges of the thread literally cut into the masonry (easy in soft brick, can be hard work for large screws in concrete) - which results in a very secure fitting that doesn't depend on outward pressure.

An additional advantage is they're easily removable.