How to fill this hole

[John Carlyle-Clarke]

I have a hole under my bathtub at ground level where the waste pipes exit through the wall. The hole an arch-shaped hole, about the size of a side plate. It has two copper pipes going through it. The hole only goes through the block layer into the cavity.

Because of our recent rat infestation, I need to fill this hole with something reasonably rodent-proof. In fact, I found a dead rat in the space under the tub yesterday!

How can I fill this hole without whatever I use pouring into the cavity? Cement? Concrete? Mesh? Expanding foam? Combination of the above? It's hard to shutter it because of the pipes. Access is obviously not great either, but not too bad.

My favourite ideas are to fill the back of the hole with foam and then fill over the front with concrete or cement, or to stuff the back of the hole with metal mesh and fill the front with expanding foam.

Any suggestions welcomed.

[sm_jamieson]

I'd probably chop up some aircrete block and mortar in. Would be quicker than shuttering and pouring anything. Or wedge in some celotex, and screw some board over the front. Don't squirt or pour anything in that could bridge the cavity. Simon.

[Lobster]

Expanding foam would be just the job (unless someone says that ratty eats the stuff.... even then, it's so easy to do I'd be tempted to give it a go first just to see if it puts him off)

David

[Mj]

Maybe having first stuffed some wire mesh into the hole & then foamed it through ~ That'll give ratty a nice surprise if he starts to chew his way back in through the foam

[nog]

Any self-respecting rat wouldn't be detered by wire mesh.

[Peter Parry]

Car body filler.

[The Natural Philosopher]

With luck he will eat it before it sets, and end up like a canoe.

[The Medway Handyman]

Agreed a cheap & easy way to sort the problem, but I thought rats did eat the stuff?

Maybe someone with more knowledge will be along soon...

[nightjar]

It is quite useless for stopping rats or mice by itself. You need to include a barrier of unchewable stuff, like wire mesh.

Colin Bignell

[nightjar]

Depends on the wire in the mesh. 10swg works well.

Colin Bignell

[Mike P]

.. >On Fri, 04 Jan 2008 18:41:37 +0000, John Carlyle-Clarke .. > wrote: .. >

.. >>How can I fill this hole without whatever I use pouring into the cavity? .. >

.. >Car body filler.

Rats can chew through concrete as we all know.

Remedy .... Create a cemet mix .. admire your result .... take one large bottle or glass and break it into many pieces .... mix broken glass shards into the cement mix, grinning all the time .... place mixture into the hole under the tub. Ratty will just love it .... not :-) ...

Mike P

[nog]

Rats don't evaluate return on effort, so will just keep going until the job is done.

[John Stumbles]

Bit of one-coat plaster or bonding plaster or browning plaster mixed reasonably stiff and shoved into the hole (with fingers if necessary).

[nightjar]

How long does it take a rat to chew through 1/8" steel wire, compared to the average life-span of a rat?

Colin Bignell

[Owain]

nightjar >>>Any self-respecting rat wouldn't be detered by wire mesh.

The partially-chewed wire can be handed down to the nth generation of rat.

Rather like we'll be doing with mortgages soon. "My great-great-great-granddaddy took this out in 2020 and by 2140 I'll have nearly paid off the front porch"

Owain

[<me9]

Or more likely, a 2.5mm T&E?