My wife and I have just bought a house. It’s relatively new, having been built in 2012, just over a year ago. Amongst the bricks of the front wall of the house there are several hard rubber or plastic things that seem to be acting as spacers, or some form of ventilation system for internal insulation, in the mortar between bricks. On the entire front face of the house I can see about five or six of them, and they seem to be of two different designs, with one set being slightly thinner and taller than the others. Their distribution doesn’t seem to form a pattern (i.e. they are not placed symmetrically about our front door in the wall, or anything like that), but they all seem to be on the lowest floor of our house, and all seem to be about chest height up the wall, with some higher than others.
Now, all of these spacers are hollow, whatever they are, with the shorter, thinner ones having a hole in them about the same diameter as a pencil, I’d say. And that’s the problem: when watering our front garden yesterday I noticed that there were wasps flying towards the holes and climbing in to the holes and disappearing!
Should these things have been left in by the builder? I’ve been trying to find a reference to them online with Google, and neither Google search nor Google images is of any use. If not, the house is still under warranty and we can get the builder to fix them (especially as they are attracting wasps!)
I’m not a builder, but was told by a contractor that these are “weepholes” to allow ventilation (dehumidification) of the inner spaces between brick and inside wall.
Mine are all on the lowest row, and I simply nuke the holes (with pesticide) when I find wasps/etc using them as doors.
Ah OK, thanks. I had come across weepholes from searching but all the pictures I had found had them as being a bit of missing mortar between adjoining bricks which isn’t what we have. Perhaps they’ve updated them with something more modern now. I’ll try the pesticide thing.
It’s not just insects but birds are getting through our brick spacers. Is there a plastic or gauze thing you can put in the space to allow air but not birds in? (UK)
If they are conventional weepholes, they’re not quite performing the same function as an airbrick, as they are not there purely to ventilate the space but to allow water build-up to escape the cavity. (see here or here). They should be positioned above the DPC / DPM, to allow any water that passes into the cavity and trickles down the inside face to escape. You should find them above anywhere there is a cavity tray installed - so at floor levels and above the lintels of windows.
That’s of course if they* are* conventional weepholes - in a new house built under 2012 or even 2010 Part L regulations they could form part of a specific (supply air) stack-effect ventilation strategy, utilising the external wall cavity as a feed for a high level heat exchanger - does your home logbook or manual mention anything about such a system? (if you have one?)
If there are wasps going in there at any sort of observable regularity, then there is a nest the other side - either in the cavity wall or in the space beneath a floor.
And as this is the UK, ‘wasps’ means yellowjackets, which implies a nest containing hundreds or thousands of adult insects. If you decide to spray this yourself, be careful - they may all come pouring out in full-on attack mode the moment you start spraying.
