Filling hole under rear extension

[chris101]

I have just come across what looks like a rat hole/tunnel under my rear extension.

I only have about an inch gap between the wall and decking to see the hole.

What would be the easiest way to fill the hole with concrete?

Never really used concrete before so any suggestions on what I need to do and how to fill this hole through such a small gap would be appreciated.

 

[JohnD]

I've had this, and the rats burrowed a new hole.

You have to kill them all first.

Get a big bottle of blue rat-poison grains, or the waterproof blocks, put down several small heaps and replenish daily for at least a week until it stops being taken.

Cover it to protect from rain, pets and hedgehogs.

If you have a rat-table, sorry, bird-table, spilling rat food, get rid of it.

 

[cjard]

http://www.screwfix.com/p/no-nonsense-expanding-foam-hand-held-750ml/45865

 

[chris101]

I have started the poison and hopefuly it should do the trick.
In terms of the hole, how and what djd you use to seal it?

 

[chris101]

http://www.screwfix.com/p/no-nonsense-expanding-foam-hand-held-750ml/45865

Rats would probably eat through that?

 

[JohnD]

I did use fine concrete, but first I rammed broken brick and concrete down with a broom handle, thinking they would be unable to burrow through it (the yard was laid on 100mm or rammed hardcore, so it was only the edges.

If the burrow slopes downwards and you use a runny mix with no large stones, it will probably run down and block the tunnel, but if you have not killed them first, they will dig a new one through earth or under your house. They may already have other entrances you have not found.

 

[vinn]

If its rats then they will have other holes/ entrances/exits.
Where they have burrowed under concrete slabs and gas smoke has been blown in its come out at various surprising locations around the slab.
Ive seen compacted wire wool used as a blocker but whether it long term worked or not i dont know?
Semi dry sand & cement might work but not on soil only in a masonry tunnel.