Next door's builder dodgy brickwork

Well I've decided I'm not going to worry about it and hopefully my builder still does a good job of my building work. Not sure about next door's builder like with the state of that tie in.

This is the postfix foundation:


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It’s not what I’d have done but I am sure it will be fine! After all many brick foundations just go down onto competent ground normally a foot or so down, the postmix is performing the same function in effect.
 
Is there a drainage strategy/fall on the area where you'll be parking - you'd said it hasn't got a roof, but how is the roller door mechanism protected from the elements
so neighbours going for a similar deal with lintel & gate/door
 
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jpaul said:
Is there a drainage strategy/fall on the area where you'll be parking - you'd said it hasn't got a roof, but how is the roller door mechanism protected from the elements
so neighbours going for a similar deal with lintel & gate/door
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The back yard (driveway) has always been concrete ever since the house was built. Although I did have half of it renewed during the first covid lockdown (see other thread) and the other half was probably replaced 30-40 year ago. I am planning on getting the whole back yard (driveway) block paved with permeable blocks from Marshalls and I've already got a few ground workers lined up to quote as soon as this building work is finished.

No idea how they make the garage door water proof but dozens of properties in my street and surrounding streets have the same set up with garage door access to their back yards for parking. There is even someone along my street who has an electric one too. So it must can be done. I've also decided to go for an electric roller door too although I'm getting a local garage door company to measure and install it rather than my builder.

Neighbour is going for similar deal yes, though they are just basically replacing what they had which came crashing down during Storm Arwen. They just had a basic up and over door.
 
Re the postcrete stuff, the Hanson datasheet says
Hanson PostFix is a simple to use fast-setting concrete mix for fixing posts in the ground.
It requires no pre-mixing before use. Hanson Postfix contains Portland cement and special additives together with sharp sand and 10mm gavel.
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TLDR your builder seems to be being a bit lazy and using the wrong product. It will hopefully turn out to be ok but the manufacturer (Hanson) really needs to confirm it complies with the requirements of 2E2.b.i) in the building regulations (assuming the ground there is not aggressive or needing special enhanced properties).

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what the concrete needs to do:
Approved Document A (AD-A) of the building regs (structure) says:
2E2 The following design provisions relate to foundations:
a. the foundations should be situated centrally under the wall;
b. for foundations in chemically aggressive soil conditions guidance in BS 8500-1 and BRE Special Digest 1 should be followed.
In non-aggressive soils, concrete should be composed of Portland cement to BS EN 197-1 and -2 and fine and coarse aggregate conforming to BS EN 12620 and the mix should comply with one of the following recommendations:
i. in proportion of 50kg of Portland cement to not more than 200kg (0.1m3) of fine aggregate and 400kg (0.2m3) of coarse aggregate; or​
ii. grade ST2 or grade GEN I concrete to BS 8500-2;​
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Hanson's bagged product for bi) seems to be their Multipurpose concrete, and for bii) their 40N concrete though this far exceeds a GEN1 and might even comply with less severe cases of aggressive ground. I wouldn't be surprised if their Multipurpose would also achieve bii) in many cases, though they don't declare this directly.

So how does this compare to what they have actually used?

The data sheet states Postfix is intended for fences etc so the builder is using it contrary to manufacturer's guidance. Naughty unless they've advised him otherwise.

The data sheet refers to
Hanson Postfix contains Portland cement and special additives together with sharp sand and 10mm gavel [sic].
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This mix may be enough to tick the requirement of item 2E2.b.i) provided the ratios comply (the mix proportions are not listed in the data sheet).

There is no statement on designated or prescribed concrete classes. (GEN1/ST2 respectively) so it presumably does not meet 2E2.b.ii
The data sheet does list a >10N/mm2 compressive 28day strength which would be similar to a GEN1 strength so that's encouraging.

Only Hanson can confirm it complies with the regs I'm afraid as they don't publish enough information on it online.

What can you do?

You (or your architect/engineer if you have employed one) could call Hanson to ask if their Postfix concrete can be used this way and how its durability compares to 2E2.b.i) of AD-A, or GEN1 to BS8500, or another concrete they would recommend for foundations. Hopefully they will say "it's not ideal but not worth digging up" and you can sleep easy.

Hope that helps.

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All concrete has aggregate in it.

I think some people are confusing cement and concrete here.

If postmix complied with building regs then they’d be publishing as such and charging accordingly.

I initially thought it was going to be a 3 or 4ft wall. A bigger one with a roller door attached… less confident.
 
If it falls down I'll sue him for money back. :(

Neighbour's brick pillars are just set on soil and maybe a bit of cement because I watched the guy do them.
 
LeeUK said:
If it falls down I'll sue him for money back. :(

Neighbour's brick pillars are just set on soil and maybe a bit of cement because I watched the guy do them.
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It'll be fine. It is just red rag to online DIY pros because the bag doesn't say "garage door brickwork foundations".
 
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