Hi all
I've been taking a good look at the outside of our house, as we have a
bit of a rat problem and I'm trying to work out where they are getting in.

We have an internal soil pipe and a few years ago the path from the bottom
of this to the drain was redone, as the 'U-bend' fitting had cracked. Cue
much smelliness ... That seems to be sorted now.

However we have heard rats from what seems to be the inside of the soil pipe
'cavity', and they presumably can get from there into the loft (they are
definitely getting into the loft).

Anyway... on the outside of the house, about 8 foot up and in this area,
there is a small (4") 'Flap Valve'. It doesn't seem to be damaged but I
wonder if small vermin might be able to get in through this?

More generally, what would the point of such a vent be? is it just to supply
a bit of air to the soil pipe cavity? We don't have an extractor fan and I
haven't been able to find reference to why this might be fitted.

A follow-on point: I can feel a slight cold draught if I feel under the
cupboards near the base area of the soil pipe. I guess this implies that the
kitchen floor is slightly open to the soil pipe cavity. Is this normal? I am
thinking of investigating with an inspection camera and perhaps blocking up
any gaps with copper mesh and expanding foam...

Thanks for any thoughts

Jon N

On 05/02/2018 23:58, jkn wrote:
Hi all
I've been taking a good look at the outside of our house, as we have a
bit of a rat problem and I'm trying to work out where they are getting in.

We have an internal soil pipe and a few years ago the path from the bottom
of this to the drain was redone, as the 'U-bend' fitting had cracked. Cue
much smelliness ... That seems to be sorted now.

However we have heard rats from what seems to be the inside of the soil pipe
'cavity', and they presumably can get from there into the loft (they are
definitely getting into the loft).

Anyway... on the outside of the house, about 8 foot up and in this area,
there is a small (4") 'Flap Valve'. It doesn't seem to be damaged but I
wonder if small vermin might be able to get in through this?

More generally, what would the point of such a vent be? is it just to supply
a bit of air to the soil pipe cavity? We don't have an extractor fan and I
haven't been able to find reference to why this might be fitted.

A follow-on point: I can feel a slight cold draught if I feel under the
cupboards near the base area of the soil pipe. I guess this implies that the
kitchen floor is slightly open to the soil pipe cavity. Is this normal? I am
thinking of investigating with an inspection camera and perhaps blocking up
any gaps with copper mesh and expanding foam...

Thanks for any thoughts

Jon N

You seem to have covered the bases, it can be difficult to keep them out
especially in old properties with party walls. Farm supply shops and
eBay have effective baits and traps. I found a nest with two dessicated
skeletons under a window sill once (rubble fill wall, the reveal was 18
inches deep). No sign of smell (but they had been there a while).