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Posted: Sat Jul 15, 2006 9:54 am
by buk
I was all set to order the bricks to build the retaining wall around my patio. The bottom course, and the backs of all the courses will be potentialy be subject to ground water exposure, so building the whole thing from engineering bricks makes sense. Especially as by ording a whole palette of one type of brick means that they will deliver them free, thus offsetting the slight increase in cost.
However, in a conversation with a professional bricky, he said that making a good looking wall from engineering bricks is much harder than with normal bricks, even for a professional. This was due to their lack of absorbtion, and tendancy to become marked? The conversation was cut short and I didn't get chance to fully understand the problems involved.
Anyone got any further information on the problems? Are they something that can be overcome by the application of care and unlimited, uncosted time? Bearing in mind I have laid maybe 20 bricks in my entire 50 years.
Are the alternatives:
1) ordering two types of brick. some engineering, some ordinary.
2) Ordering an FL quality ordinary brick and using a dpm under-up-over.
Code: Select all
coping  =======
dpm    -------| """"""""""""""""""""""""""""""""""""""""""""""""
1 Â Â Â Â Â Â | B | | [ooo]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
2 Â Â Â Â Â Â | B | | [ooo]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
3 Â Â Â Â Â Â | B | | [ooo]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
4 Â Â Â Â Â Â | B | | [o0o]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
dpm    -------| [ooo]\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
footing  //////////\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\
As indicated, I intend putting a slotted pipe ground drain behind the wall, but (I assume), that won't prevent absorbant bricks becoming saturated under storm conditions without a dpm?
My aim is to use my time to offset cost wherever possible, and I'm wondering if my thought that using "time and care" to avoid delivery charges and purchasing dpm is a false economy here?
Thanks, buk.[/color]
Posted: Sat Jul 15, 2006 5:56 pm
by dig dug dan
Its hard to give sound advice without actually seeing what you are trying to do.
I always buy "flettons" or "rejects" for backing up and building up from the footing to ground level. IN the 14 or so years I have been trading, this has never been a problem. But, I do backfill behind the wall with crushed/rubble for drainage, and depending on the height, allow perp ends .
You are wasting your money with dpc, and flettons only cost about 20p each.
Choose a nice sand faced brick for the brickwork you will see, and if your builders merchants stock them, there should be none of this nonsense about charging. Our local merchants do not charge, and they shouldn't if you are ordering your sand/cement from them all in the same load.
Engineering bricks are very difficult to get a good finish on them due to the fact they do not absorb water, the muck has to be stiffer to stop sloppy joints, and it makes the job more difficlut. If you are finishing the wall with brick on edge, there comes a problem at the end of the wall with the last brick as you cannot hide the holes!
Engineering bricks are best suited for under ground work, such as manholes.
Posted: Sun Jul 16, 2006 12:46 pm
by buk
dig dug dan wrote:and depending on the height, allow perp ends .
Allow perp ends to what? 
It took me a long time to make sense of that bit--assuming that I now have.
Perp ends:- Perpendicular ends. The vertical joints between adjacent bricks in a course?
Allow perp ends:- periodically leaving a perp end unmortared thereby allowing water to flow through from the back to the front of the wall?
Posted: Sun Jul 16, 2006 1:36 pm
by dig dug dan
Sorry, i should have explained that. Your last point says it in one. It allows any water to flow through, instead of remaining behind the wall!
Posted: Sun Aug 06, 2006 6:07 pm
by lutonlagerlout
well it depends on what sort of bricklayer you are
theres brickies and theres brickies as they say
flettons should NEVER be used below ground
they absorb a lot of water and when the winter comes they fail
it can make a nice feature using blue staffords from below ground up to 150mm above ground level then continue in whatever facers you like.
depending on your ground it might be an idea to use sulphate resisting cement
hope this helps
tony
Posted: Mon Aug 07, 2006 3:43 am
by Suggers
Flettons are shite, shite, shite, and more shite. - put them on the inside skin.
Never visible.
Leave engineering bricks inside your fireplace. -
Leave carving skiis for the Sunday Roast.
Go and get some lovely, local hand-made bricks - you will be proud of the job for the rest of your life - we only borrow this time - your work will outlive you.....
Hello Luton Geezer - I'm down the road in Chesham - fancy a pint?
ps - I think Flettons should be illegal.
Posted: Mon Aug 07, 2006 4:06 am
by buk
lutonlagerlout wrote:well it depends on what sort of bricklayer you are
theres brickies and theres brickies as they say
flettons should NEVER be used below ground
they absorb a lot of water and when the winter comes they fail
it can make a nice feature using blue staffords from below ground up to 150mm above ground level then continue in whatever facers you like.
depending on your ground it might be an idea to use sulphate resisting cement
hope this helps
tony
Tony,
As I tried to indicate with my ascii art, the wall is a retaining wall between my sunken patio and the lawn. The footing are directly onto the chalk bedrock so none of the bricks will be underground on the patio side.
I am a raw beginner as far as my bricklaying skills are concerned, but I have time in my side and I'm pretty patient.
Having taken the warning regarding engineering bricks to heart, I've pretty much settled upon Mile End Red Multi (from Jewson). They are an FL rated brick, with a strength rating of 42 N/mm2 (which seems to be pretty high) and an absorbsion rating of < 12% (which appears to be pretty low).
Does that sound good?
Also, I was advised to use 50% sharp sand in mixed with the builders sand I already have for the mortar. As purchase of the sharp sand would be an additional expense, I'm keen to know if this is a necessary step?
Cheers, BUK.
(ps. Do the Hatters still play at their old ground, or did they get a new one yet? They had been talking about a new one for 10 or more years when I moved away from Harpenden something like 20 years ago.)
Posted: Mon Aug 07, 2006 5:34 pm
by lutonlagerlout
hi buk and suggers
well the fact you are on chalk is very very good as chalk is permeable,this means you shouldnt get a lot of water laying around.
what part of the country do you live in??
look around at your local bricks and try to keep the colours and styles to match your own
i.e. suggers lives in chesham(must be rich!) so his local bricks are bovingdon berrys,duntons and chesham multis from matthews brickyard,sadly none of these are really suitable for beneath ground,but they do look like they belong in that area.
and to be brutally honest buk if you are not a brick layer you WILL balls up your patio wall
i have seen it time and time again ppl saying "yeah but i have loads of time" etc.
if you want to input let the brickie lay them ,you load out and knock up the muck
it takes approx 4000 hours to learn bricklaying to a good standard, maybe 8000 to be top class
i doubt you have this time
when i need the house painting i work saturday and sunday ,then pay the painter to do it
bit like bartering
hope this helps
regards tony
Posted: Mon Aug 07, 2006 5:37 pm
by lutonlagerlout
PS
yes the hatters still play at kenilworth road
and yes they are still talking about a new ground
regarding sharp sand it will make the mix stronger but if you are going to do this you need to add lime to make the mix more plastic
for a small wall just make sure the mix is 3:1 soft sand :OPC
regards tony