Parapet bricks moved after frost

[Ss.shor]

I am a builder who last year completed and orangery with a parapet roof, using LBC bricks as per the spec of plans to match existing house.

Customers has complained, Bricks have now moved due to frost damage, a structural engineer has been out and said he has experience that LBC bricks sbouldnt have been used on this style of build I.e garden wall styles. I have found various forums stating the same thing but it clearly isn't widely known that these bricks should have been used as other builders like my self also are unaware, Can anyone advise. If its the bricks at fault am I liable to repair? And if not how do I prove otherwise given the fact I wasn't aware they shouldn't have been used. Any help will be much appreciated.

 

[Charlie George]

Is there a coping on the parapet wall with a suitable overhang/drip, and is the brickwork fine on the rest of the orangery? it's unlikely to be the brick at fault.

 

[Ss.shor]

Yes, all has been done correctly. Building control signed off over a year ago. All brick work below lintel in fine, just above lintel height where parapet roof is damaged due to forst, on 2 sides of the build that doesn't get direct sun light. The side that gets the sun is not affected. I have over 13 years experience bricklaying and never once had an issue with my brickwork after until now, having said that I also haven't used London bricks before now either. After an inspection the engineer stated he'd has experience of this happening before and gave the best appropriate advice. The problem is, it may have happened before but its not widely known, so I'm at a abit of a loss as to how I prove I'm not at fault.

 

[Mottie]

Who specified them in the first place? You’ve only worked to someone else’s specification which I assume was agreed by the client.

 

[^woody^]

moved due to frost damage

Implies a design fault if the parapet has moved from frost action. But could be a quality issue if moved from poor construction.

Fundamentally, if it was not your role to specify, and you used the materials specified by other professionals then you are not responsible if those materials were incorrectly specified or failed to perform.

However, you do, as a professional have some duty to point out incorrectly specified materials or practices or design issues within your expertise - as bricks would be.

Taking this into account, if the bricks were F2 rated then they would be normally suitable for frost resistance, and you as a builder would have no liability, or concerns or extra duty in using them. You would not be expected to know about detailed design other than the common requirements for a parapet - DPC, copings, drips etc.

However, whoever designed the parapet has extra duty (from extra expertise) and they should know that despite any brick being frost rated, that does not mean it is suitable for exposed locations such as parapets, and the mortar correct too. Plus the fact that the parapet should be properly designed to dispel water and be weather resistant.

Of course, the bricks may be a bad batch, and that may be your responsibility to sort out with your suppliers, or if the fault relates to quality of construction but otherwise if the cause is incorrectly specified bricks.

First thing is to determine what the actual cause of the defect is.

 

[Ss.shor]

The drawings stated bricks to match house not saying to use LBC. However they where the bricks used on the existing house.

That's what I'm trying to figure out what caused it. Is it to much water getting through or is it the bricks or a combination of both, I'm just confused in this case water getting into the bricks and then the bricks failing. Customer is saying bad work man ship and ultimately demanding a repair for free but as per structural engineers report he's saying different, customer is still not happy with that so im trying to gather as much evidence as I can to not only find the cause but to the porve that I may not actully be at fault.

Also the face of the build that gets the sun in winter is fine while other side that doesn't get any due to buildings around is affected.

 

[Charlie George]

Is it the brick failing or the mortar? ie is the brick crumbling or is the brickwork coming loose? and what mortar/mix ratio was used in the parapet wall and also how is the wall finished on top and where is the dpc in parapet wall?
It could be that not one single factor or person is at fault, maybe a compromise can be agreed between parties and you do it at a reduced cost.

 

[Ss.shor]

The mortar is failing.
Mix was 5.1 ratio
Cavity was closed of with slate
With a coping on top 30mm either side

Like above all brick work was signed off by building control before this happened. This is the side that doesn't get any direct sun light, the other side that does get direct sun light hasn't been affected

 

[Charlie George]

What time of year was this built? looks to me it was built in cold weather, and maybe not protected, you should also have a cavity tray with weep vents installed too, overhang could be more aswell,and does it have a drip? what ratio mortar was used,NHBC recommend 3.5 to 1, on one job i did they insisted on using sulphur resisting cement for exposed areas.
I don't think you'll have any luck with the brick company as the issue doesn't seem to be the brick, if theres no cavity tray(can't see weepholes) the problem will only get worse if not sorted.

 

[Ss.shor]

Winter but bricks where laid in appropriate weather, frost proof used bricks covered with hessian. Dpc with weeps was done over lintel hight.

I've never heard of a mix of 3.5 being used ever also that mix would be to strong for these type of bricks. When I served my time in college stressed the mix ratio, making sure the mix was weaker than the bricks

5 to 1 mix was used also this build was signed of and inspection was carried out at every stage of built with no issues. So this is the problem, I have done by the book as per my experience and trade. But need to know what to do next, I told customer I was happy to repair at my own cost even though report suggests bricks are problem but ask he would kindly supply the scaffolding. He has point blank refused to do so and is demanding I rectify solely at my own cost even though a report tells him how the damage has occurred. If this goes to court I need to have relevant evidence to back up hence why I've ask on this hub. This goes beyond what I've ever done before and never once been questioned of my brickwork in the 13 years I've been trading so I really don't know what to do.

 

[Charlie George]

3.5 to 1 mix is recommended for exposed areas and below DPC, in hindsight you could have used lime in your mortar which would have helped, the parapet wall needs its own cavity tray the whole length, to me it looks like frost got to it after laying, and with you using frost proofer it must have been cold, good luck with it, but i think your'e going to have to take it on the chin, and we've all been there