I need my house to be re-rendered -advice on getting the job done properly!!

[alibarnie]

Hi all, this is my first post on the forum.

I have to admit from the beginning that I am not a plasterer, but am in need of some good render! Hopefully by being a potential costumer I will be immune form any abuse or ridicule on the site! ;-)

A large chunk of the current sand and cement render has fallen from the breeze block walls of our house, and the remainder render sounds hollow on tapping (blown!), so we looking to get the whole lot taken of and re-rendered. Until viewing this forum we'd been hoping to avoid sand and cement in favour of a more modern system to avoid further cracking. It seems that from reading the forum that if sand and cement is correctly applied then such problems shouldn't arise.

Our current difficulty is the price difference between the various quotes that we have received -ranging from £6000 to £13000, and that each company is offering a different system. The cheaper quotes are from larger companies with pushy sales people, whereas the more expensive quotes are from more local trademen.

So far we have been offered sand and cement, GRC, wetherby and monocouche. I think all companies are offering a K1.5 silicone finishing colour coat, which seems to come with a crack resistant gaurantee, but again from reading the forum it seems that it may not be fully crack resistant!

Any advice on how to decide on the most appropriate system would be much appreciated, which is the least likely to crack or is that more dependent on how it is applied? What issues should we be wary of with the lower quotations - will it be a case of 'pay peanuts and get monkeys'? Ultimately I felt that I didn't trust any of the larger companies, but am trying to convince myself that they are cheap because they specialise in render rather than just being crap!!

Finally, is there anyone near Ely (Cambs) who wants to come and do the job??

Thanks in advance for any help,

Alastair (Ali).

Ps is this post too long???

 

[johniosaif]

Good post actually, are you expecting advice or cheaper quotes?why don't you hack all the render off yourself, it will make it easier to price and advise.

 

[alibarnie]

Looking for advice primarily, and I hadn't considered hacking off the render myself -thanks very much!

Not looking for cheaper quotes, but would rather the local guys could match the larger companies!

 

[johniosaif]

Get it hacked off , get labourers in ,then it will be easier to get sensible quotes, well build in for the unknown,

 

[alibarnie]

That makes sense - thank you. Might try to see if companies will adjust quotes accordingly if we hack off the render.

Any advice regarding best rendering system, is there much to chose between them?

 

[plasterjfe]

Large companies will supply your job with a labour force of subbies who are on a very cheap rate (paid by the metre probably so speed is what they will be after) A local say, family firm will be making a living from it and should be looking to maintain his reputation.

Really its tricky there are good good firms out there but they wont be the cheapest but nor should they be the dearest.

Its right that correctly mixed and applied sand and cement is a good render but personally if your house is breeze block as in what u normally find internally then I would opt for a lightweight polymer. Make sure the breeze block istreated ffirst.
Are u sure iys not concrete block ?

 

[johniosaif]

I am an old fashioned rendering guy, there are pros and cons to all the ways regardless of the spiel that you will hear, sand and cement has stood the test of time and the materials are cheaper, some will push the coloured render, some insulation and render, watch out for building regs too, make sure you are not spending money and then be told you have to do something else to comply, get all the info and facts before you commit..

 

[plasterjfe]

I dont like mentioning about brands on the open forum. Where u based

 

[alibarnie]

Certainly one of the larger firms claimed to have 17 teams working at anyone time, so it would make sense that they would be unlikely to be skilled workmen. The three larger companies all had incredibly pushy salesmen which immediately put me off - all offered cheaper deals but only if we signed there and then!!!

You can tell I am not in the building trade -yes I do mean concrete block not breeze blocks!! What would examples of a lightweight polymer be. I am based in Cambridgeshire near Ely.

Is it standard for some cracks to eventually form with sand and cement, and can a flexible silicone type final coating be used over sand and cement to hide any cracks that may develop?

Thank you both for your advice so far- very much appreciated!

 

[plasterjfe]

Ok on concrete block a well installed sand cement render will be fine. Breeze block really should not be used for render. Anyway we ruled that out.

There are some lightweight products aimed at blockwork that is 3.6n ish rather than the better 7n.
I think merlin covers your area and could advise u from here on but I aint seen him on here for ages.

 

[johniosaif]

You can have cracks with any of the renders,modern or new, its more about the people doing it and their knowledge and desire to make a lasting job,what I would do or ask to be done is to scud the whole area to be plastered first with a splatter coat of sand and cement mixed very wet with sbr in the mix at a strength of three to one, leave at least for a day, the first coati would apply would be five to one ratios sand and cement with waterproofer and plastizer , leave this coat scratched for a week, don't let it dry out too quickly, damp if necessary or in real heat cover to protect, if you are really concerned about cracking you can add fibres into the first coat and even have render mesh embedded in the first coat, I would if it was my house, after seven days ,you can apply second coat mixed at a ratio six one one sand cement and lime, also add fibres but reduce them to one handful a full mix,sme re the drying if very hot cover and damp down for a week,
there may be some who disagree but ignore them ha ha, only kidding , lots of ways and viewpoints and some make perfect sense.

 

[alibarnie]

Thanks again for you advice guys - has really helped. I think I may be coming round to the idea of sand & cement - had the same opinion from a local plasterer. I like the idea of adding fibres or render mesh to the mix. Is there any benefit of an additional chemical bonding agent being use onto the blockwork eg PVA, or again is it a case the if the jobs's done properly that this isn't required.

Hopefully a final question: would a silicone based final colour coat be suitable for finishing sand/cement render and would it hide fine cracks that may develop, and should it last longer? I read somewhere that if defects do develop in such coatings that they are harder to rectify -does that sound right?

Thanks again for the really helpful advice.

Ali.

I feel like I owe you both now! I am a vet so if you need any advice regarding cats, dogs etc then feel free to ask!!!

 

[johniosaif]

No pva outside ever, sbr yes , you can put it on 1/1 to water in two coats three hours apart or add it in the mix but its not cheap. Coloured render is not my world so someone else will answer that, I have a dog and two cats, and vets are very expensive in London.

 

[alibarnie]

Cheers! Vets in London definintely charge more than elsewhere! Always worth shopping around -prices vary considerably. If you take your pets for a vaccine or neutering then most of the larger vet chains will be cheapest, but if you they need any kind of surgical procedure than typically a smaller vets will be much better value.