Concern about the work of stonemason

adidas

Hello all

I'm having some work done on the exterior of my house and I wanted your advice.

One of the things I'm having done is the stone bay windows restored.

I had brand new primed and undercoated wooden sash windows installed prior to this as moving out the previous windows would have been likely to cause damage to the bays. The windows are not sealed as they would have been sealed onto the old paint that would have needed to come off. I was waiting to seal them after restoration of the stone and finally gloss them when they are in.

I am dissatisfied with the manner in which the stone work is being conducted. On agreeing to the job I was assured that the windows would be protected and water wouldn't come into the property due to the technique they would use.

Few issues:
-the jet washer has caused water to come in round the windows onto the plaster work and paint inside.
-the front door (1920s) was jetwashed under causing water to come into the hallway
-problems with inadequate shielding between properties and neighbour complaining
-the sash window wood not being covered up and now there is bare wood where they haven't been properly protected from the corrosive chemical mix

-the jet washing and chemical mix has stripped paint off the door
-bizarrely starting to 'finish' the bottom bay window before even stripping the top bay window causing corrosive mix to fall onto the stone work below causing pits and dents

Am sure the actual stone work itself will be done satisfactorily but concerned about this collateral damage. Is it normal to spend hours jetwashing the masonry to remove paint?

I raised first 4 issues yesterday with the boss.

My concern was the wall would need replastering and he disagreed saying he could paint it. I have discussed it with my partner and feel the wall needs to dry out first and we'll need to wait and see thereafter. I'm well aware that this may have been an issue but disappointed to be told this could be prevented by targeted washing (otherwise I could have used a different company who did not use such techniques).

He also said it couldn't be helped about the water coming in as the windows weren't sealed. And advised me to seal the windows but of course needs taking off again to properly restore the stone.

My personal opinion is I'm not sure that the jetwashing high pressure gallons of water onto the seams of the windows would help (and I'm bewildered why hosing low pressure that would have prevented this from happening wasn't used around the more sensitive bits).

Regarding the division: nothing was done yesterday and jet washing continued.

Today: I spoke to them again to cover up the windows as the duct tape had come off and to partition between next door.

The partition was put up, but the windows were not covered up. And some bits duct tape not properly covering them. Today I have a look at them and see the brand new windows are blotchy and paint come away completely in some areas.

More water around the windows and in the hallway too.

Having already discussed things with them and little care taken to protect the windows, I'm growing increasing concerned. I think the jet washing has been done. Their work schedule is haphazard and they come and go when they like. I've been made aware since I engaged them in work that they are juggling at least 3 pieces of work.

I'm sure that raising the issue again will be told 'we'll paint your windows'. Though I'm concerned that given the blotchyness and patches missing that they'll do an uneven and careless job, on what essentially are brand new windows.

I'm really dissatisfied and annoyed that despite raising concerns they haven't been resolved. I'm worried about allowing them to paint the windows when they are not painters/decorators and given their poor due diligence to existing fixings, might make matters worse.

- What are my options?
- Am I compelled to allow them to repaint it?
- Am I allowed to with-hold funds or seek a quote for 'making good' their damage from another source?

Would be grateful for your advice. Many thanks

hollydays

I find some of your post confusing.
When you say you were told it could have been prevented by targeted washing , what exactly are you saying?
To make an omelette you have to break a few eggs.

What does the boss say about the amount of jetwshing that was done, and why are you confident they will Make a good job of the stonework .
You need to keep a very close eye on them
And get constant reports of exactly what they are going to do, as the supervision seems poor.

thearchitect

[FONT=&quot][FONT=&quot][FONT=&quot]Firstly, a caveat. Stonework [FONT=&quot]can be a complex issue and it is difficult to make any firm comments without having had a chance to [FONT=&quot]see the masonry and attempted cleaning operations. [FONT=&quot]Advice on the internet, no matter how well qualified the p[FONT=&quot]rovider, is [FONT=&quot]never a substitute for [FONT=&quot]close inspection and[FONT=&quot] professional advice.

[FONT=&quot]You do n[FONT=&quot]ot detail the work being under[FONT=&quot]taken [FONT=&quot]in any great deta[FONT=&quot]il, hence further caution is required. A [FONT=&quot]dense [FONT=&quot]granite or basalt [FONT=&quot]will [FONT=&quot]respond to cleaning very different from[FONT=&quot] a [FONT=&quot]softer, more porous sandstone[FONT=&quot] or limestone property[FONT=&quot] for example.[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]

[FONT=&quot][FONT=&quot][FONT=&quot]On the face of it your complaint is simply about substandard work which has led to damage to internal decorative linings and to [FONT=&quot]joinerwork, most notably the [FONT=&quot]new sash & case windows. In the first instance the contractor has to be given the opportunity to rectify these errors, although it is open to you to agree to a cash deduction instead.

[FONT=&quot]Should you allow the contractor to remedy the [FONT=&quot]damage to the plaster jambs then yes, it would normally take a while to dry out. Particular caution would be required if these where [FONT=&quot]finished on the hard using a modern gypsum-ba[FONT=&quot]sed m[FONT=&quot]aterial [FONT=&quot]such as T[FONT=&quot]h[FONT=&quot]istle Multi-Coat inasmuch as they are less tolerant of damps/salts which can arrise if traditional solid wall construction.

[FONT=&quot]However there are other issues that worry me. [FONT=&quot]Aggressive cleaning of traditional stonemaso[FONT=&quot]nry is generally opposed by English Heritage/Historic England and Historic Environment Scotland as it can actually cause significant damage to the matrix of softer stones - leading, in time, to accelerated weathering and failure. For e[FONT=&quot]xample:

[FONT=&quot]1. [FONT=&quot]High pressure jet washing [FONT=&quot]may loosen[FONT=&quot] the surface matrix of the stone, encouraging delamination and[FONT=&quot]/or creating microscopic roughening of the surface which encourages algae/lichen growth.

[FONT=&quot]2. Likewise powerwashing an unpointed building can[FONT=&quot] allow significant amounts of water to saturate the wall which can become trapped, for example if a cement-based mortar is subsequently [FONT=&quot]used, leading to dampness problems.

[FONT=&quot]3. Most chemical cleaning agents are highly aggresive and [FONT=&quot]can further weaken the stone surface, especially if not fully neutralised in accordance with manufacturer's instructions.

[FONT=&quot]4. Beware cement[FONT=&quot] and cement-based repair products! Walls ha[FONT=&quot]ve to breath, and cement is fairly famous for[FONT=&quot] being p[FONT=&quot]retty imperveous. Only natural lime mortars should be used and joints must be fully repointed - not just the top half inch or so - if they are to be weather tight.

[FONT=&quot][FONT=&quot]Once the building has [FONT=&quot]dried out, I would [FONT=&quot]suggest you look at a traditional sand mastic ("trowelling mastic")[FONT=&quot] around your new windows[FONT=&quot], painted to match, as this will adhere to the stone and timber far better than a modern polysulphide mastic.

Also note for future reference that best practice is to prime and undercoat all timber surfaces such as this prior to installation, including inbuilt faces in contact with solid walls[FONT=&quot], with only the gloss applied in-situ.[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]
[/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT][/FONT]

adidas

I find some of your post confusing.
When you say you were told it could have been prevented by targeted washing , what exactly are you saying?
To make an omelette you have to break a few eggs.

Yes I am aware that there may have been damage though generally not taking care to cover the windows from caustic cleaning chemical is my concern

What does the boss say about the amount of jetwshing that was done, and why are you confident they will Make a good job of the stonework .

The boss feels the jetwashing was required to remove the paint. I am not confident as in 100% sure, though I need to wait and see

You need to keep a very close eye on them

This will be difficult as I work full time and their hours are ad hoc so I'm never really sure when they're going to turn up

And get constant reports of exactly what they are going to do, as the supervision seems poor.

I am trying to, though it is a bit like talking to a brick wall. I am constantly onto them and seem to get vague answers.

adidas

Thanks the architect and hollydays for your advice.

adidas

Firstly, a caveat. Stonework can be a complex issue and it is difficult to make any firm comments without having had a chance to see the masonry and attempted cleaning operations. Advice on the internet, no matter how well qualified the provider, is never a substitute for close inspection and professional advice.

You do not detail the work being undertaken in any great detail, hence further caution is required. A dense granite or basalt will respond to cleaning very different from a softer, more porous sandstone or limestone property for example.

The sills are traditional bathstone and the walls brick, in good position with minimal loose joints.

On the face of it your complaint is simply about substandard work which has led to damage to internal decorative linings and to joinerwork, most notably the new sash & case windows. In the first instance the contractor has to be given the opportunity to rectify these errors, although it is open to you to agree to a cash deduction instead.

Yes my concern is about the manner in which the work is being conducted and damage to fixings. In essence do I have to let a stonemason who already is careless in managing to section off the wooden windows paint (prime and undercoat) the windows themselves? My concern is given his substandard work that they'll be left in a mess and I'd rather get a proper painter/decorator as they aren't qualified or experienced in this area.

Should you allow the contractor to remedy the damage to the plaster jambs then yes, it would normally take a while to dry out. Particular caution would be required if these where finished on the hard using a modern gypsum-based material such as Thistle Multi-Coat inasmuch as they are less tolerant of damps/salts which can arrise if traditional solid wall construction.

However there are other issues that worry me. Aggressive cleaning of traditional stonemasonry is generally opposed by English Heritage/Historic England and Historic Environment Scotland as it can actually cause significant damage to the matrix of softer stones - leading, in time, to accelerated weathering and failure. For example:

The house is not in a conservation area.

1. High pressure jet washing may loosen the surface matrix of the stone, encouraging delamination and/or creating microscopic roughening of the surface which encourages algae/lichen growth.

Thanks for letting me know this. I note the surface is being smoothed and sanded after paint removal.

2. Likewise powerwashing an unpointed building can allow significant amounts of water to saturate the wall which can become trapped, for example if a cement-based mortar is subsequently used, leading to dampness problems.

3. Most chemical cleaning agents are highly aggresive and can further weaken the stone surface, especially if not fully neutralised in accordance with manufacturer's instructions.

I believe this is the one of the reasons for the copious jetwashing.

4. Beware cement and cement-based repair products! Walls have to breath, and cement is fairly famous for being pretty imperveous. Only natural lime mortars should be used and joints must be fully repointed - not just the top half inch or so - if they are to be weather tight.

The walls are due to be repointed with lime mortar mix.

Once the building has dried out, I would suggest you look at a traditional sand mastic ("trowelling mastic") around your new windows, painted to match, as this will adhere to the stone and timber far better than a modern polysulphide mastic.

Thanks for this I will have a chat to the sash window company when they return.

Also note for future reference that best practice is to prime and undercoat all timber surfaces such as this prior to installation, including inbuilt faces in contact with solid walls, with only the gloss applied in-situ.

Thanks again. All the windows were primed and undercoated though due to the methods used in cleaning the stone some of this has damaged the priming and undercoating.

thearchitect

This is a consumer rights forum, rather than a building advice one, but I'm afraid that you now have me worried. Put plainly:

1. Aggressive cleaning of masonry is a bad idea as, depending upon the substrate, it can damage the stone. Brickwork is usually, but not always, less susceptible to damage but chemical agents are still best avoided..

2. You cannot "sand" natural stonework. Attempts can be made to redress or repolish ashlar dressings, the latter using a carborundum, but that is a technically fraught exercise.

3. What kind of lime mix? There are many different varieties with different performance characteristics, not all of which will be suitable for all circumstances.

4. You cannot unilaterally refuse the contractor the opportunity to rectify his defect (i.e. the painterwork); what you can do is insist on a reasonable standard and, if he fails to meet this, reject the workmanship. Alternatively you can come to a cash settlement with him and have your own subcontractor undertake the work.