Tanking

[grays85]

hi.. is this a bad word, it seems to be?

I /we are having our old cheese rooms tanked out, with approval from the conservation officer and planning dept, we are not having the walls sealed with reneder or having a dpc fitted, as this will cause the moisture to move to somewhere else, we are having cavity trays fitted into the floor around the edges of the room and a sump pump, the idea is that any moisture still passes through the wall, drops in to the cavity tray, fitted all around the edges , this runs to a sump chamber and will be pumped away. the process covers all the walls with batton and impermeable sheeting and can be completely reversed to show the original building..
Is that so wrong, opinions greatly appreciated
The basement consists of two rooms, which are 2.5mtr x 3mtr each, one will be a store (boiler room / washing machine store and the other store will be a games room.. officially as there a steel bars in the window and only one stair into the rooms they can only be called store rooms!!

 

[Nemesis]

You are doing exactly the right thing.

Go have glass of wine and be happy!

 

[grays85]

phew... thanks nem' i think i'll make it a double then

 

[Nemesis]

Have one for me!

 

[chuckey]

Can you not dig down outside and put in external drainage and an external plastic membrane and insulation?
Frank

 

[Nemesis]

Why?

This approach works and has the blessing of the CO.

 

[grays85]

we have to do the work internally as at present the flagstone floor is bedded on compressed clay, which has water coming through occassionaly. there is even a channel that the water has eroded.
we have as part of the process to take out the flagstones (which have to be individually marked and re sited in the original position and bedded on a bed of sand and then pointed with lime mortar) there has to be a concrete slab fitted below the flagstones to stop the water coming through it..

hic decided to have another glass nem; :roll:

this will keep the rooms dry..hopefully

 

[K8]

if the floor is going to be totaly impermable (concrete) where will that water go that currently comes through the floor that you mention?

 

[grays85]

the cavity tray around the room is sited on pea gravel where the water rises through and is then pumped away

 

[Juju]

This sounds interesting. Would it work in a cellar? Our cellar is very damp and although we have a dehumidifier working hard down there, I've been wondering about other solutions which, apart from reducing the damp, would make it a more usuable room. It's just used for storage at the moment but could make a laundry drying and ironing room or gym (the stationary bike shoved in the corner could actually get used!) But I'm not sure how your system would work in our case when the water table rises and floods our cellar - it's only happened once in the past 9 months (with the summer floods) since we've lived there but guess it will probably happen again.

 

[Penners]

The tanking method that attracts a bad press involves hacking off the plaster and covering the interior walls with a multi-coat "waterproof" render.

Its questionable reputation is based on the fact that (a) it has a high failure rate, (b) even if it works it often doesn't last long - maybe 10 years, and (c) it is very difficult to get off the walls once it has stopped doing the job that it was put on to do. So it's not readily reversible.

 

[chuckey]

Nemesis- Why? Because of the complexity of the sump pump, and its supply, and its filter, and its outlet plumbing and its access hatch and its alarm when the water level rises and the pump does not start and the likelyhood of getting an identical replacement when it fails. oh yes and an alarm when its power feed fails.
Apart from the above I think its a brilliant idea.
Frank

 

[grays85]

i've seen the application in situ.. yes the sump could fail yes the back up sump could fail yes the electric could fail and yes the alarm could not go off, lots of if's and maybes, however when the water table rises at present the cellar floods. an unholy mess and as such renders( no pun) two rooms useless..
I don't want to render the room as it at present has no dpc, like the rest of the house, it never had one and as such if i were to line it internally or externally the moisture would go somewhere else, either causing me or my neighbour a problem. I've opted on this method as the moisture movement is not impeded but controlled, (subject to electric supplies / back up and plumbing..(i'm a plumber so should be cheaper
so hopefully all will go well and if the room ever gets owned by someone else all they need to do is take the panelling off the wall and it will be exactly as it was before.

 

[Cottage]

I have been thinking of doing something similar with a cellar. The main thing is that we would like to have, say the top half of the stone walls exposed in the cellar. The cellar has a coal hole. The house has no DPC and is late 1600.

Has anyone done something like this? I am thinking that it would not work using your method.