# Do you pour concrete into tub drain areas in slab?



## bigbaby (May 7, 2009)

My plumber has put dry redimix into the holes in the slab that are at the tub drains. I have read that the reason wet concrete is not put into the hole is in case repairs are needed.

But putting dry redi mix there seems silly, since it might get wet and become hard.

I have heard that some plumbers put in sand first and then a layer of wet concrete on top to prevent termite entry. 

How do you handle this situation? I live in an expansive soil, termite-infested region. 

Any help would be appreciated.


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## thom (Nov 3, 2006)

Around here they get left open. Trying to seal a floor slab is almost impossible. If there are termites or ants below, they will get through any plumbing entries as well as at the perimeter slab/stemwal areas.


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## TimelessQuality (Sep 23, 2007)

ya.. soil pre-treatment is sop here

you need the flexibility to fine tune hookups


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## KillerToiletSpider (May 27, 2007)

Horse trough in the backyard is all you need for bathing, problem solved.


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## bigbaby (May 7, 2009)

All slabs here are treated for termites by code and by necessity.

I've read a lot of pros and cons on the inet for leaving the redi mix dry or wetting it. Called the plumbing inspector, who of course, has been doing this business for 40+ years (yawn) and he said it's always left dry and over time gets wet from moisture in the area. Sounds iffy to me.

I had the plumber come out and wet it and now it's hard and a good cover to prevent termites.

Imho, probably the best way to do it is to put gravel down there and then a 2" layed of mixed concrete poured over the top. This way if repairs ever need to be made they can possibly hammer out that top layer without damaging the pipe. In my case for this job, the plumbers had already done the deed so I went ahead and told them to wet it. Next job I will request the better way in advance.


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## ASMCHICO (Aug 24, 2009)

I work with a few outstanding plumbers. They always want to mortar (wet) the hole to keep the termites & varmints out. 

After much debate, I have decided no to do this on my jobs. I too live in a termite rich environment. Those little suckers can traverse some very tiny cracks. Almost any separation or cracking is enough to let them in. 

Hopefully your plumbing doesn't leak and attract pests! :laughing:

We do mostly remodel work in old places that always seem to get termites in one place or another. My solution is to fill the hole with galvanized wire and gravel/rocks. Most of my stuff is multifamily properties. We are usually asked to leave an inspection plate adjacent to the tub plumbing so the management can do annual leak inspections. The gravel and mesh is enough to keep the squirrels out, yet leaves a very easily treated hole. The pest guys can saturate the hole and know that it is 100% treated. When there is a concrete fill, they can't treat as easily or effectively. 

IMHO either way is great - just don't over fill it and screw the guy that will follow you some day!


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