DIY cellar tanking with a membrane system

Discussion in 'UK DIY' started by Danny Monaghan, Jul 5, 2006.

  1. Has anyone done/have experience of using a membrane system to tank a cellar?

    It seems not to be a complicated process, but I haven't seen any details
    from someone who has done it themselves and appearances can be deceptive :)

    As cellar converstion costs seem to run around the £40K mark, and I have
    a £20K budget, I'm thinking I could save a heavy amount by having the
    underpinning and floor lowering done by a contractor but doing the
    tanking and finishing myself.

    Is this a viable route?
    Danny Monaghan, Jul 5, 2006
    #1
    1. Advertising

  2. Danny Monaghan

    Bookworm Guest

    Danny Monaghan wrote:
    > Has anyone done/have experience of using a membrane system to tank a cellar?
    >
    > It seems not to be a complicated process, but I haven't seen any details
    > from someone who has done it themselves and appearances can be deceptive :)
    >
    > As cellar converstion costs seem to run around the £40K mark, and I have
    > a £20K budget, I'm thinking I could save a heavy amount by having the
    > underpinning and floor lowering done by a contractor but doing the
    > tanking and finishing myself.
    >
    > Is this a viable route?


    Could you define what you mean by a 'membrane system'?

    The probs with a bonded membrane is that a high water drive can disbond
    the membrane from a weak substrate as is normally found in previously
    damp brickwork. Once it is disbonded water builds up behind and
    disaster results.

    Look at cementitious waterproof coatings which will allow the substrate
    to breathe. There are several on the market. I sell one but am not
    going to advertise. Most can withstand about 20 metre head of water and
    can be, and in fact must be, applied to a damp substrate. They are
    applied by brush,roller or airless spray. They do not look very pretty
    but can be overclad, (do not pierce the coating for batten fixings).

    There are Epoxy/Bitumen coatings available but a) They do not breathe
    and are OK for rearside applications (positive water pressure) and b)
    Bitumen smell seems to last forever. Same rule applies regarding
    fixings.
    Bookworm, Jul 5, 2006
    #2
    1. Advertising

  3. Danny Monaghan

    Bookworm Guest

    Hugo Nebula wrote:

    >
    > Go on, say it. Vandex by any chance?
    > --
    > Hugo Nebula


    Wrong. There are about 6-10 manufacturers out there. I sell for one
    nobodys ever heard of and only sell to the trade. The poster would
    never be able to buy the product I sell even if I named it.

    Just trying to impart some of my experience of selling Tanking
    Membranes and Tanking Coatings over the past 20 years.

    Probably will be met with cyncism by some of the trolls who inhabit
    this group.
    Bookworm, Jul 6, 2006
    #3
  4. Bookworm wrote:

    >
    > Could you define what you mean by a 'membrane system'?
    >
    > The probs with a bonded membrane is that a high water drive can disbond
    > the membrane from a weak substrate as is normally found in previously
    > damp brickwork. Once it is disbonded water builds up behind and
    > disaster results.
    >
    > Look at cementitious waterproof coatings which will allow the substrate
    > to breathe. There are several on the market. I sell one but am not
    > going to advertise. Most can withstand about 20 metre head of water and
    > can be, and in fact must be, applied to a damp substrate. They are
    > applied by brush,roller or airless spray. They do not look very pretty
    > but can be overclad, (do not pierce the coating for batten fixings).
    >
    > There are Epoxy/Bitumen coatings available but a) They do not breathe
    > and are OK for rearside applications (positive water pressure) and b)
    > Bitumen smell seems to last forever. Same rule applies regarding
    > fixings.
    >


    I was thinking about something like this from Newton Membranes:

    http://www.newton-membranes.co.uk/System500.htm

    Basically from what I've read, these systems that control water flow
    rather than holding it back are better, and seem to be simple to install.
    Danny Monaghan, Jul 6, 2006
    #4
  5. Danny Monaghan

    Owain Guest

    Bookworm wrote:
    > Hugo Nebula wrote:
    >>Go on, say it. Vandex by any chance?

    > Wrong. There are about 6-10 manufacturers out there. I sell for one
    > nobodys ever heard of and only sell to the trade. The poster would
    > never be able to buy the product I sell even if I named it.


    So no-one could object to your naming it, then.

    Owain
    Owain, Jul 6, 2006
    #5
  6. Danny Monaghan

    Bookworm Guest

    Danny Monaghan wrote:

    > I was thinking about something like this from Newton Membranes:
    >
    > http://www.newton-membranes.co.uk/System500.htm
    >
    > Basically from what I've read, these systems that control water flow
    > rather than holding it back are better, and seem to be simple to install.


    I have looked at the Newton Website and they quote:

    'Newton Titan Sump and Pump to remove excess water that may enter from
    behind the sealed membrane system.'

    I rest my case.

    A 100% perfect way of tanking in such circumstances is what is called
    'curtain injection' whereby holes are drilled at predetermined spacing
    through the wall and over the whole walls surface, to the outside
    substrate. An Acrylic Resin Gel is then injected at high pressure which
    form a waterproof curtain between the subsoil and the outside of the
    wall. Thus you are preventing the water from entering the walls in the
    first place.

    It is very expensive and needs special pumps and experinced operatives.
    Being used worldwide to seal leaks in tunnels, CTRL, London
    Underground, Tunnel between Denmark & Sweden, Dublin Port Tunnel etc
    etc.
    Bookworm, Jul 6, 2006
    #6
  7. Danny Monaghan

    Bookworm Guest

    Owain wrote:

    > So no-one could object to your naming it, then.
    >
    > Owain


    And then be flamed for advertising! Do me a favour? Address the guys
    problem or shut up. If you aint got nothing to say on the subject dont
    bother posting.
    Bookworm, Jul 6, 2006
    #7
  8. Danny Monaghan

    Fash Guest

    Danny Monaghan wrote:
    > Bookworm wrote:
    >
    > >
    > > Could you define what you mean by a 'membrane system'?
    > >
    > > The probs with a bonded membrane is that a high water drive can disbond
    > > the membrane from a weak substrate as is normally found in previously
    > > damp brickwork. Once it is disbonded water builds up behind and
    > > disaster results.
    > >
    > > Look at cementitious waterproof coatings which will allow the substrate
    > > to breathe. There are several on the market. I sell one but am not
    > > going to advertise. Most can withstand about 20 metre head of water and
    > > can be, and in fact must be, applied to a damp substrate. They are
    > > applied by brush,roller or airless spray. They do not look very pretty
    > > but can be overclad, (do not pierce the coating for batten fixings).
    > >
    > > There are Epoxy/Bitumen coatings available but a) They do not breathe
    > > and are OK for rearside applications (positive water pressure) and b)
    > > Bitumen smell seems to last forever. Same rule applies regarding
    > > fixings.
    > >

    >
    > I was thinking about something like this from Newton Membranes:
    >
    > http://www.newton-membranes.co.uk/System500.htm
    >
    > Basically from what I've read, these systems that control water flow
    > rather than holding it back are better, and seem to be simple to install.


    I am in the process of installing something very similar to the Newton
    system in my basement. I've used Wykamol since the sales guy was happy
    to sell to me as a non-qualified installer. They also sent an
    installation instructions CD which was pretty clear. By far the biggest
    problem is managing awkward shapes/corners etc. When it came to doing
    the floor I built a small cardboard model of the floor and cut strips
    of card to represent lengths of membrane and used this to work out all
    the overlaps, cut and fold lines etc. When laying it with my general
    constractor (no previous experience of the stuff) we used the model as
    a template. Only cut 1 bit wrong out of 60sqm.

    I used it in a refurb where I was putting in a new floor and rather
    than use their perimeter drainage I installed perforated land-drains
    (with geotextile wrapped round to prevent clogging) running to a sump.
    Buy the sump pump separately as it's much cheaper and use something
    like a small cold water tank as the sump chamber.

    In total cost of the membrane stuff came to £750 and it's a pretty big
    cellar, and an extra ~£150 for the sump pump and associated gubbins.

    My cellar has rubble stone walls so the other problem was making
    successful fixings. As a result I hung it like curtains as less fixings
    required and will put up a stud wall inside this. If you've got brick
    walls it would go up like a dream and you can either use a version
    suitable for plastering directly onto, or fix battens to your 'plugs'
    and dry-line.

    This is definitely a DIY job and suitable for almost all types of
    building (mines a listed Georgian townhouse). If you want further
    specific advice email is as presented.

    Fash
    Fash, Jul 6, 2006
    #8
  9. Danny Monaghan

    Fash Guest

    Forgot to say I also did floor lowering but not by underpinning.
    Underpinning not a sensible option (for me) as walls are 600mm thick
    and rubble stone so liable to keep falling into any trench dug out for
    underpinning. If you don't need much height gain (I've gone from 6'3"
    to 6'8") then you can use a reinforced 'bathtub' floor where the
    reinforcing forms an upstand at the edge of the room, which when
    concreted forms a ring beam which holds back the earth at the base of
    the foundations. The whole floor needs to be reinforced to prevent any
    problems from heave lifting the middle of the floor.

    I did all the digging out myself (with a little help from friends paid
    with beer), put in the under floor drainage, and had a contractor put
    in the sub-base and reinforced concrete, with a joint venture on the
    membrane as I wasn't confident they'd give it the same attention to
    detail that I would.

    The other thing you need to consider is humidity as the membrane system
    works best when not fully sealed at the ceiling so you still need to
    deal with water vapour. I'm planning to put in a heat recovery
    ventilator which can deliver 4 air changes/hr but with the same heat
    loss as 1 change/hr. If this turns out not to be sufficient I'll add a
    wall-mounted dehumidifier.

    Total conversion cost including drainage, contractor, a new RSJ across
    the room, stud walls, flooring (including undertile heating), lighting
    etc. is estimated at £12-15k and gives me a room which is 19' x 13'.

    If you want to share my ignorance further just ask.

    Fash
    Fash, Jul 6, 2006
    #9
  10. Danny Monaghan

    Steve Walker Guest

    Bookworm wrote:
    > Owain wrote:
    >
    >> So no-one could object to your naming it, then.
    >>
    >> Owain

    >
    > And then be flamed for advertising! Do me a favour? Address the
    > guys problem or shut up. If you aint got nothing to say on the
    > subject dont bother posting.


    You wouldn't be flamed by anyone worth worrying about.
    Your expertise would be helpful to many readers, myself included.
    Steve Walker, Jul 6, 2006
    #10
  11. Bookworm wrote:

    > 'Newton Titan Sump and Pump to remove excess water that may enter from
    > behind the sealed membrane system.'
    >
    > I rest my case.
    >


    Sorry, I don't get what you mean here.
    Danny Monaghan, Jul 7, 2006
    #11
  12. Fash wrote:

    > ...snipped for size...


    > If you want to share my ignorance further just ask.
    >
    > Fash
    >


    Thanks for the info. I'll email you for more details.
    Danny Monaghan, Jul 7, 2006
    #12
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. Andrew Barnes

    Tanking a cellar

    Andrew Barnes, May 5, 2005, in forum: UK DIY
    Replies:
    8
    Views:
    778
    Doctor Evil
    Jun 20, 2005
  2. Appin

    Tanking a cellar

    Appin, May 6, 2005, in forum: UK DIY
    Replies:
    0
    Views:
    241
    Appin
    May 6, 2005
  3. avocado

    Budget cellar tanking

    avocado, Jul 1, 2007, in forum: UK DIY
    Replies:
    5
    Views:
    1,466
  4. Danny Monaghan

    Cellar Tanking Membrane Ventilation

    Danny Monaghan, Apr 17, 2008, in forum: UK DIY
    Replies:
    2
    Views:
    396
    Andrew Gabriel
    Apr 19, 2008
  5. Tanking a cellar

    , Jun 20, 2007, in forum: Home Repair
    Replies:
    2
    Views:
    264
Loading...

Share This Page