DIYbanter

DIYbanter (https://www.diybanter.com/)
-   UK diy (https://www.diybanter.com/uk-diy/)
-   -   waterproofing a flat concrete roof (https://www.diybanter.com/uk-diy/325913-waterproofing-flat-concrete-roof.html)

TMC[_2_] July 13th 11 12:38 AM

waterproofing a flat concrete roof
 
Hi All

ex council house outside store roof 100mm thick concrete area about 4m x 3
metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution

any recommendations

Regards




Dean Heighington[_2_] July 13th 11 08:05 AM

waterproofing a flat concrete roof
 
"TMC" wrote:
Hi All

ex council house outside store roof 100mm thick concrete area about 4m x 3 metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution

any recommendations

Regards


Is there any provision for the rainwater to drain off or does it just
puddle up and stay trapped?
is there a fall?

--
What else are opposable thumbs for? Get to me at
masterfix{at}btinternet{dot}com

TMC[_2_] July 13th 11 09:01 AM

waterproofing a flat concrete roof
 

"Dean Heighington" wrote in message
...
"TMC" wrote:
Hi All

ex council house outside store roof 100mm thick concrete area about 4m x
3 metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution

any recommendations

Regards


Is there any provision for the rainwater to drain off or does it just
puddle up and stay trapped?
is there a fall?

--

yep slight fall to the back with gutter and downpipe

Regards


Steve Firth July 13th 11 09:19 AM

waterproofing a flat concrete roof
 
TMC wrote:

Looking at the fibrous paints or other low cost solution

any recommendations


The usual solution in places like Italy where flat concrete roofs are
normal is to lay a waterproof screed on the roof. This requires the roof
to be clean and dry before you start.

http://www.izonil.com/uk/improver.html

For example.


Lobster July 13th 11 10:09 AM

waterproofing a flat concrete roof
 
On 12/07/2011 23:38, TMC wrote:
ex council house outside store roof 100mm thick concrete area about 4m x
3 metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution


Sounds identical to one I did myself once. IIRC I used bitumen paint as
a cheapo solution, as I knew I'd be selling the place not long afterwards.

Seemed to do the job well enough; I can't vouch for it's longevity but
think if I'd been intending on keeping the property for a long time I'd
have chosen something more durable. Indeed, the purchaser's surveyor
flagged it as a future maintenance issue.

David

Jim K[_3_] July 13th 11 12:57 PM

waterproofing a flat concrete roof
 
On Jul 12, 11:38 pm, "TMC" wrote:
Hi All

ex council house outside store roof 100mm thick concrete area about 4m x 3
metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution

any recommendations

Regards


epoxy paint - garage floor styley? can't see any +'s to "Fibrous" in
that scenario?

Jim K

The Natural Philosopher[_2_] July 13th 11 03:15 PM

waterproofing a flat concrete roof
 
Lobster wrote:
On 12/07/2011 23:38, TMC wrote:
ex council house outside store roof 100mm thick concrete area about 4m x
3 metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution


Sounds identical to one I did myself once. IIRC I used bitumen paint as
a cheapo solution, as I knew I'd be selling the place not long afterwards.

Seemed to do the job well enough; I can't vouch for it's longevity but
think if I'd been intending on keeping the property for a long time I'd
have chosen something more durable. Indeed, the purchaser's surveyor
flagged it as a future maintenance issue.

David

yeah. Concrete itself is pretty impervious, depending on the grade.

Anything that soaks in a bit of a plasticky or tarry nature will improve
it immensely.

Probably one of those render waterproofers will do.



TMC[_2_] July 13th 11 05:48 PM

waterproofing a flat concrete roof
 

"The Natural Philosopher" wrote in message
...
Lobster wrote:
On 12/07/2011 23:38, TMC wrote:
ex council house outside store roof 100mm thick concrete area about 4m x
3 metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution


Sounds identical to one I did myself once. IIRC I used bitumen paint as
a cheapo solution, as I knew I'd be selling the place not long
afterwards.

Seemed to do the job well enough; I can't vouch for it's longevity but
think if I'd been intending on keeping the property for a long time I'd
have chosen something more durable. Indeed, the purchaser's surveyor
flagged it as a future maintenance issue.

David

yeah. Concrete itself is pretty impervious, depending on the grade.

Anything that soaks in a bit of a plasticky or tarry nature will improve
it immensely.

Probably one of those render waterproofers will do.

good thoughts I will investigate further as I think that the problem is a
crack in the concrete



Phil L[_3_] July 13th 11 06:36 PM

waterproofing a flat concrete roof
 
TMC wrote:
Hi All

ex council house outside store roof 100mm thick concrete area about
4m x 3 metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution

any recommendations

Regards


having atempted all of the suggestions in this thread over the past thirty
years, I have found only one solution and that is to use a product called
'cromapol'

http://www.nwepaints.co.uk/acatalog/...nCoatings.html


I've done a few concrete rooves with this and had no problems at all, it's
expensive, because it works.

Don't bother with anything available from B&Q et al, they also have
expensive sealants, but none of them work on cracked concrete

It's available in black, white and grey



Dean Heighington[_2_] July 13th 11 08:24 PM

waterproofing a flat concrete roof
 
"TMC" wrote:
"Dean Heighington" wrote in message
...
"TMC" wrote:
Hi All

ex council house outside store roof 100mm thick concrete area about 4m x 3 metres

has rasied front and sides (a lip about 25mm high)

Never been felted

Looking at the fibrous paints or other low cost solution

any recommendations

Regards


Is there any provision for the rainwater to drain off or does it just
puddle up and stay trapped?
is there a fall?

-- yep slight fall to the back with gutter and downpipe


Regards


Having read all the other posts since my reply this am, I would also
recommend the cromapol product or there's another called aquapol, I
think... Check out JJ Roofing supplies or Wedge roofing, but again, it's
not cheap- about £90 a tin retail, £60 trade. For a cheaper way of
remedying it as a trial.... If you can find the crack get a tube of Sika
Flex
http://m.screwfix.com/details.htm?id=79250
and use that to fill the joint, it's great stuff.

Hth
Deano

--
What else are opposable thumbs for? Get to me at
masterfix{at}btinternet{dot}com


All times are GMT +1. The time now is 03:11 AM.

Powered by vBulletin® Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2004 - 2014 DIYbanter