On Tue, 22 Jul 2008 17:21:33 +0100, Mary Fisher wrote:

I have read that by the end of the year a wasps nest in the ground or
in a loft etc may be the size of an armchair,

That would be VERY unusual if you're in UK.

and would expect that if this is taking place inside a partition wall,
it would achieve about the same overall bulk but be spread out some
metres between the two walls. As far as I can see there is no way
they can get inside the building from the partition. I have read that
wasps
are quite beneficial to the environment and especially the gardener so
my
inclination is to leave it be, and try to remember not to run towards
the
airbrick shouting and waving my arms and banging things, etc. I think
a
wasps
nest is deserted after one season- I wouldn't be quite so keen if I
thought
this was going to repeat year after year.



All the above is correct - except that the sprad of the nest will not be
more than a metre, I think, depending on the depth of the cavity. Most
wasp nests are perhaps the volume of a large football but not a large
beachball. Their shape is determined by the space they occupy.

I'd go along with the spread a metre or so diameter from the entrance
hole. I had one in the eaves of a loft, that was about 3' long 18" high at
the front and about 9" high at the rear, discovered it at the end of the
season. A little larger than a beach ball...

Thanks for being concerned and intelligent about it!

Agreed if thier flight path or entrance isn't going to bring you and them
into regular close contact leave 'em be. They are good at keeping garden
pests down.

I only have two very slight concerns. One is damp bridging from the outer
to inner skin of the cavity wall via the nest and the other possibilty of
blocked ventilation into the cavity. Wasps using airbricks as access isn't
all that common I wonder if this brick is damaged in some way either
aplastic one with naggered flyscreen or broken brick one making the
ventilation holes just that little bit larger.

When they have died off in the autumn gone it might be worth taking that
brick out and replacing it, at the same time you could clear the cavity of
the nest.

--
Cheers
Dave.

With the benefit of a nice warm location for their nest, they may well not die off until well into winter.

I successfully got rid my first cavity wasps' nest simply by blocking off the access to it. I think I got that one quite early. It didn't work the second time because they found other ways out that were less congenial to me, so I made a strategic decision to reopen the original entrance.

Wasps chew wood to make their nests. The second cavity wasps' nest I had was just below a wooden windowsill, and I could hear them chewing at the windowsill, it was quite loud.

There are aerosol wasp nest killers that are very effective and easy for the kind of wasps nest that is confined inside a hole such as a cavity wall. The trick is to use it at night (that means well after dark) when the wasps are mainly dormant. That way you aren't interfered with, and you get most of them as they are all at home. I have used them a couple of times with success.

When the wasps start losing their way and regularly coming into the part of the house that you occupy, as they will, you may wish you'd got rid of it sooner. You can end up with dopey wasps crawling over your bedding in the early morning, (he says from experience) which sets yourself up perfectly for the sting.

"echinosum" wrote in message
...


The OP wants to leave it be.

Mary