Tiler who wants to use PVA

[lukeo]

Tiler coming to do a bathroom next week, I know he'll want to use PVA.

I have some BAL tile primer, do I prime it before he gets here? or ask him to use it? Either way, telling some how to do their job isn't an ideal situation. How would you react if a customer suggests you don't use a product that you use on every job?

Also, on the PVA debate. I've read lots of comments saying PVA isn't waterproof. Well, some PVA is waterproof. You can get exterior grade PVA like so:

http://www.screwfix.com/prods/35205/...proof-PVA-5Ltr

[sWe]

It's not just about wether or not it's waterproof (waterproof isn't the same as water resistant) or not. It's about chemical combatibility.

As far as I know, if you put PVA in direct contact with cement based materials, the PVA will deteriorate due to a reaction with the alkali in the cement, forming acetic acid. The bond between the PVA and the adhesive will deteriorate with time.

I hate it when customers do things when the responsibility is ultimatly mine, without asking me. I also hate it when customer tell me what to do, or what to use. If I were you, I'd deal with this somewhat subtly.

[TilingLogistics]

PVA is a definate No No. However, as SWE says I hate it when customers tell me what to use as well. Conversley speaking though if he wants to use PVA he is wrong it should be an APD. I always use BAL. Good Luck

Kev

[MICK the Tiler]

As sWe has said you need to tread lightly here us tilers are a temper tantrum type of trade.

I certainly would not do anything with the job before the tiler arrives.

However you must convey the message that you do not want pva used. but in saying so you must also be prepared to get another tiler who is willing to listen to your requests if he refuses. It's all part of being in control of the situation, you are parting with your hard earned money and the tiler if reasonable and proffesional will listen to your requests.

[lukeo]

Originally Posted by sWe

As far as I know, if you put PVA in direct contact with cement based materials, the PVA will deteriorate due to a reaction with the alkali in the cement, forming acetic acid. The bond between the PVA and the adhesive will deteriorate with time.

So on that basis, this product http://www.screwfix.com/prods/35205/...proof-PVA-5Ltr which claims to be "suitable for bonding cement based screeds and renders" is actually totally useless??

As regard the tiler not using PVA. It's the same with any trade isn't it?

Like telling a plasterer you don't want dot and dab. You assume tradesman know their job. We once had a plasterer of 25 years experience dot and dab with duplex boards. I questioned at the time whether that was possible as I didn't think it was. He said it sure was and did it, they all fell off.

[sWe]

Originally Posted by lukeo

So on that basis, this product http://www.screwfix.com/prods/35205/Sealants-Adhesives/PVA/PVA-Sealant-Primer/UniBond-Waterproof-PVA-5Ltr which claims to be "suitable for bonding cement based screeds and renders" is actually totally useless??

Well, manufacturers design their products in systems, so it's always important to follow their instructions, and to use product combinations recommended by them.

One thing most of the people on these forums seem to agree on, is that Unibond should be avoided. There are posts every week on tiles falling off or something like that, and more often than not, Unibond materials have been used.

Originally Posted by lukeo

As regard the tiler not using PVA. It's the same with any trade isn't it?

Like telling a plasterer you don't want dot and dab. You assume tradesman know their job. We once had a plasterer of 25 years experience dot and dab with duplex boards. I questioned at the time whether that was possible as I didn't think it was. He said it sure was and did it, they all fell off.

Time served can be an indicator of skill and knowledge, but ultimatly, it does not guarantee anything. As a customer, you should always ask for references. Even then you can't be 100% sure you're hiring a good craftsman.

The following is generally true though:

Buy cheap, buy twice. This goes for quotes as well as materials.

[Varley]

Originally Posted by lukeo

How would you react if a customer suggests you don't use a product that you use on every job?

I would refuse to do the job to be honest, but in this instance you would be correct, a priming agent should be used, pva is not a primer it is a sealer. Good luck with the situation mate, it's a tricky one.

[dock]

Lukeo

I used to be involved in Research and Development of adhesives, grouts etc and

pva is NOT water resistant and never will be............................................peri od!!

Exterior grade pva will have another monomer, probably a vinyl ester, incorporated with and once dried and cross linked the additional monomer may well result in the co-polymer being water resistant

When tiling with ready for use adhesives these days it is very rare that priming is required..............Mapei, Ardex, Bal tech. services will concur with this.

dock

[LM Ceramics]

your right though bout pva i always prime walls now but i know a few tilers who use pva there are two ways you could look at it

1) you could prime the wall for him if it was me i wouldnt be offended id give you a pat on the back (caus im lazy)

2) you could tell him when he turns up that you have bought some primer for him to use im sure he would say nice one for that


if he says its alright ive got a tub of pva then just tell him u prefer primer if he spits his dummy out then find another tiler

good luck anyway

[Wingn]

If it were me I'd leave the primer sitting in your bathroom for when he arrives.

Personally if I walked on to a job and seen primer sitting, I'd use that rather than using up my own.

[whitebeam]

Originally Posted by lukeo

So on that basis, this product http://www.screwfix.com/prods/35205/Sealants-Adhesives/PVA/PVA-Sealant-Primer/UniBond-Waterproof-PVA-5Ltr which claims to be "suitable for bonding cement based screeds and renders" is actually totally useless??

As regard the tiler not using PVA. It's the same with any trade isn't it?

Like telling a plasterer you don't want dot and dab. You assume tradesman know their job. We once had a plasterer of 25 years experience dot and dab with duplex boards. I questioned at the time whether that was possible as I didn't think it was. He said it sure was and did it, they all fell off.

Had a builder tell he wanted the same board's dot and dabbed on an job but had been advised by the supplier they would be ok . I tried to convince him otherwise, Did'nt listen and fell off. Never heard a supplier get such an ear bash over the phone by the builder like that one.

[garythetiler]

i have found the replies to this post very informative i didnt know about the compatability issue with cement based produts but it seems to make sense as pva is extensively used by plasterers and plaster is a gypsum based material i have always used sbr which is a styrene butidene which is compatible with cement based produts but also you must be careful when using this as an admix/sealer as it is can effect grout colours as it reacts to ultra violet light