Dot n Dab vs sand n cement

[spreadandlay]

Hello wise strong shoulders,
I have a job to do, its a 1960's ex council house , brick internal walls,
The plaster has fallen off so needs re doing, right up the stairwell, and all rooms downstairs, ( blockwork walls upstairs so i think the render got better key) i think boarding will be easier? he has asked me to price it, he does not care either way, i just wondered what everyone else would use?
Thanks for your opinions

 

[Micilin]

You might lose your stair stinger, window cills with dot and dab.

Sand and cement with waterproofer will make a great job of your ground floor walls forever.

If you need thermal insulation, a dot and dab would be better, but less hardwearing and won't be damp proof.

My house, 9" solid 30s, I hacked all off, floated with waterproof sand and cement(straight and plumb) and then fixed thermal boards (foam backed) with nailable plugs , then skimmed it up.

 

[spreadandlay]

Thanks for your reply, makes sense, however, the sills will be going anyway and i think if i do it tight on the stairs i could still have the stringer, would you still advise it?
Why would you go for waterproof render ?
cheers

 

[external]

because he finds it difficult to work without it!why w/p something that shows no sign of damp?to the op what are you best at?but me id render if all things were equal!

 

[Micilin]

because he finds it difficult to work without it!why w/p something that shows no sign of damp?to the op what are you best at?but me id render if all things were equal!

Not at all, external -be serious !!

A waterproofer with fungicide costs much the same as plasticiser, and gives you workability. You can have even suction on every wall and float the whole house before skimming, without having to hose it down (as per an earlier suggestion on this forum ) which gives you uneven suctionand makes a mess .And without having to do anything else to equalise the background.

You can skim it two days after floating, or ten days after floating and still have the same background. If you are not used to plastering (as per your average DIY person ) you want as much time to skim as possible, not a high suction wall . Look how many people here post about walls that have crazed skimming etc because of high suction!!

This makes it easier for the non professional.

As an added bonus, your wall is damp proofed!

Why NOT use it if appropriate?

 

[external]

micilin my friend ,i offer you this no malice to your self or anyone else but it may help you understand my aversion to w/p!
for a long time i've used and enjoyed the benefits of w/p,stuffs a joy to work with,makes dashing a joke,lets you lay a gable an float it on your jack,takes the hard work out of render,but if your at it onsite, something gives ,and you've gone off spec your dead meat,anyways did a job a fair few years ago,hack off and dash,scratched with w/p then dashed,called back cause of damp in upstairs b/r,seems my scratch has sealed in moisture that the cavity would have dealt with ,my bad!i was never asked for or priced w/p,cost me the best part of a grand to fix it.
w/p will work well 90% of the time ,but if it goes tits up and you weren't asked well!

 

[Micilin]

micilin my friend ,i offer you this no malice to your self or anyone else but it may help you understand my aversion to w/p!
for a long time i've used and enjoyed the benefits of w/p,stuffs a joy to work with,makes dashing a joke,lets you lay a gable an float it on your jack,takes the hard work out of render,but if your at it onsite, something gives ,and you've gone off spec your dead meat,anyways did a job a fair few years ago,hack off and dash,scratched with w/p then dashed,called back cause of damp in upstairs b/r,seems my scratch has sealed in moisture that the cavity would have dealt with ,my bad!i was never asked for or priced w/p,cost me the best part of a grand to fix it.
w/p will work well 90% of the time ,but if it goes **** up and you weren't asked well!

Next time wear garlic !!

 

[Micilin]

On more serious note, how did damp come through if you had damproofed the wall?

I can see your aversion if you could not justify using it (i would always include in my quote whatever I was using eg s/s beads, plasitc beads etc etc) but hardly the same as saying I recommended it because I can't render without it!!!!!!!!!

No offence taken, but beware of drawn out , pedantic argument!

 

[external]

i avoid drawn out pedantic arguments on principle,i've never used pedantic,how much a bag?
never mind ,you answer the pedantic questions an ill try the ones on render

 

[external]

sorry micilin ,in answer to you question,before the render there was no damp(i skimmed the house out months before ,clean a a whistle)when ive done there is ,nothings changed but my work,you got the degree work it out!

 

[Micilin]

sorry micilin ,in answer to you question,before the render there was no damp(i skimmed the house out months before ,clean a a whistle)when ive done there is ,nothings changed but my work,you got the degree work it out!

No offence taken, but it is curious.

How did a coat of render stop the cavity working? How did they sell that theory to you? Did you fill it up with render?

It looks like the house that was 'clean as a whistle ' also had damp on the inside skin of bricks - surely the client can't have used both statements.

No rain, no leaks ?

In that case it sounds like the condensation in the room was able to soak into the wall before you rendered. When you rendered with waterpoofer, you stopped the condensation soaking in, so it stayed on the surface.

Perhaps if you were able to prove this, you would have saved time and money. It wouldn't have taken a degree , just a bit of tin foil

If you had used wp properly, any damp coming in from outside would be behind the render, and not on the skimmed surface.

I've never seen one fail where done properly.
90% is not a good return rate if you render properly - right preparation, right mix, right application, right thickness etc

One in ten jobs failing ? -



Miaow........

I don't sell pedantry by the bag, it comes in bulk!!

 

[external]

never found out what caused the damp,because thay wanted the w\p scratch gone on this aspect(and the rest should they show damp within a resonable time),so i hacked off and did again and all was fixed,damp went,i was on domestic at the time so took it on the chin ,as you now reputation is everything on domestic an you cant afford to leave a bad job
at a guess id say the roof line and or gutter were at fault cause the damp was around the lintle but i couldnt see anything.