brick piers??????

hi all im looking in the asa for the standards relating to brick piers but cant find them if anyone knows what page to look on that would be great.also has anyone done brick piers as this is our first owner builder stage i need all the help i can get.our soil is reactive clay we have to have 1mtr deep holes not sure how wide or if i can fill them with concrete then build piers from ground level upwards any help would be appreciated but be nice guys sometimes you can be brutal.!!!!!if you dont ask youll never learn!!!!!!

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Originally Posted by bingoshelley

hi all im looking in the asa for the standards relating to brick piers but cant find them if anyone knows what page to look on that would be great.also has anyone done brick piers as this is our first owner builder stage i need all the help i can get.our soil is reactive clay we have to have 1mtr deep holes not sure how wide or if i can fill them with concrete then build piers from ground level upwards any help would be appreciated but be nice guys sometimes you can be brutal.!!!!!if you dont ask youll never learn!!!!!!

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Most brick piers are built from the ground level up. :doh:

Not sure Ive seen anything Asa on brick piers, brickwork in general yes, but piers? :?

Brickwork is exactly the wrong material to be using in reactive clay anyway!

Why not use steel piers, they won't crack?

P
:wink:

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Originally Posted by bitingmidge

Brickwork is exactly the wrong material to be using in reactive clay anyway!

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Why?
Most of the older houses in Melbourne are built on them. :?

If the concrete comes to ground level (or a tad below) the bricks aren't in the reactive soil

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Originally Posted by echnidna

If the concrete comes to ground level (or a tad below) the bricks aren't in the reactive soil

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Arhh, now I see, you are asking if the bricks will disintegrate in the reactive soil.

No they wont.
Modern bricks are burnt so well when fired that they are impervious to almost most things on the planet.

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Originally Posted by bitingmidge

Brickwork is exactly the wrong material to be using in reactive clay anyway!

Why not use steel piers, they won't crack?

P
:wink:

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the reason were using brick piers is its the cheapest option for us as budget is virtually non existant i got quoted 13k for a slab and just under that for steel doing it ourselves so we have to do brick as its a hell of alot cheaper.if we do them properly and take our time im sure they will last the test of time:U

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Originally Posted by Brickie

Arhh, now I see, you are asking if the bricks will disintegrate in the reactive soil.

No they wont.
Modern bricks are burnt so well when fired that they are impervious to almost most things on the planet.

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thanks brikie i did see a picture of a brick pier in as1684 under concrete footings but no imformation like what width of hole needed what size metal tie rod (12y?) if the hoop iron goes under first or second row of bricks and with the ant cap how do you put it on if the tie rod is sticking up do you cut a hole in middle and slide over?wouldnt that effect the performance of the ant cap or do you plug the hole somehow.also where does the damp proofing go?????sorry so many questions ive looked everywhere but cant find simple answers.:;

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Originally Posted by echnidna

If the concrete comes to ground level (or a tad below) the bricks aren't in the reactive soil

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thx echidna thats what i thought but is there a particular strenght of concrete i need to order and how do i work out how much i need?????

Whats the pier doing? I is it holding up anything (load bearing)?

Do you have a picture of where it is to go?

Because you are in clay some footings have to go down to non-reactive soil. However an engineer really needs to provide you with a footing detail for you particular location (your plot)

I would say the footing will extend 150mm from the outside of the pier in any direction.

eg: 350mm x 350mm pier would 650mm x 650mm footing

The footing depth is the tricky one without seeing anything.

An ideal pier would be 350mm x 350mm with a galv 10mm rod up the centre from the footing, core filled with 25/15/80 concrete.

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Originally Posted by autogenous

Whats the pier doing? I is it holding up anything (load bearing)?

Do you have a picture of where it is to go?

Because you are in clay some footings have to go down to non-reactive soil. However an engineer really needs to provide you with a footing detail for you particular location (your plot)

I would say the footing will extend 150mm from the outside of the pier in any direction.

eg: 350mm x 350mm pier would 650mm x 650mm footing

The footing depth is the tricky one without seeing anything.

An ideal pier would be 350mm x 350mm with a galv 10mm rod up the centre from the footing, core filled with 25/15/80 concrete.

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hi autogenius the building inspecter told me to go down 1mtr deep we are building a house so they will be load bearing above ground will be 450mm so i figured i could dig the holes 1mtr fill with concrete well nearly full then build brick piers up to 450mm was planning on doing 2x2 bricks not even sure what bricks i can use for load bearing i have some solids also ones with 3 holes in them.as you can probably tell absolutely no experience here but due to finances have no choice but to try and do it ourselves.its all very well for people to say get a tradie so its done properly but getting a tradie for anything up here is a nightmare and an even bigger one when you get the bill.laying a 8.4 mtr x 15.0 mtr slab on flat as ground was as the concreter said a rough qoute of 13k maybe more so its out of our market.thx for your help though:doh:

Ive been out Wyche way a few times and have taken notice of the area and sort of taken notice of the ground, most of the advice you will get here is the advice they give to the city folk, they dont take into consideration the needs of country people.

I know the Building code is supposed to encompass all, but it doesnt, Ive lived in the country long enough to see that there is a difference from country to city codes.

I assume the building inspector wants a 600 x 600 footing 1 metre deep

Al, its more like difference in interpretation of codes rather than different codes.
In some place the "building inspector" isn't qualified as such, he's the health inspector etc etc.

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Originally Posted by echnidna

Al, its more like difference in interpretation of codes rather than different codes.
In some place the "building inspector" isn't qualified as such, he's the health inspector etc etc.

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I know Bob, Ive lived out in the bush for over 20 years, so I know what its like....:p

Bend over and bow, saying very nicely , yes sir.

I've bin there done that too, these City Slickers got no idea of the bush.

Though you can bamboozle them sometimes if yer diplomatic

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Originally Posted by echnidna

I assume the building inspector wants a 600 x 600 footing 1 metre deep

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he hasnt actually said the width as we didnt know at the time what material we were using .and you are very right about country inspecters he is 85 yrs old and so laid back its frightening seeing as im responsible for this house for a long time when we sell i dont want to cut too many corners.not safety ones anyway.what strenghth of concrete would i need to fill the holes?and how do i work out the amount to order thx:no:

Tis so long since I've done a foundation I've forgotten the concrete grade needed.

Volume = Quantity x length x width a depth

Volume = 1 hole x .6 x .6 x 1 metre = .36 cubic metres per 1 footing

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Originally Posted by echnidna

Tis so long since I've done a foundation I've forgotten the concrete grade needed.

Volume = Quantity x length x width a depth

Volume = 1 hole x .6 x .6 x 1 metre = .36 cubic metres per 1 footing

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thx for that i just got quoted $182.00 +gst per cubic mtr of concrete delivered 30km one way.seemed a bit high to me but not sure???

If you're referring to brick 'pillars' then the footing size is worked out in relation to the load it's carrying. i.e. roof type, roof area, single storey etc. I would engage a structural engineer to do the calc's.
The soil type only relates to the founding depth not the size of the pad.

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$182.00 +gst per cubic mtr of concrete delivered 30km one way

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$200 per cube is about right.

We did an O/B job too and half of it is on brick piers, reactive clay soil.

The engineer's design included specs for brick pier footings. I'd suggest you hire an engineer - as it will make a lot of these things easier for you. You can design some things off span tables but I had engineering detail for strip footings, pier footings, retaining walls and bracing/tie-down for the frame. Cost me about $1800 but covered my backside and removed the guess work.

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Originally Posted by silentC

$200 per cube is about right.

We did an O/B job too and half of it is on brick piers, reactive clay soil.

The engineer's design included specs for brick pier footings. I'd suggest you hire an engineer - as it will make a lot of these things easier for you. You can design some things off span tables but I had engineering detail for strip footings, pier footings, retaining walls and bracing/tie-down for the frame. Cost me about $1800 but covered my backside and removed the guess work.

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Thx for that we will be using all brick piers i was quoted 650 for the engineer to design footings but my architect has said she will speak to her engineer mate and put it in the plans for me all up she is only charging me 900 so im pretty lucky with that side of things i just wanted a heads up so i knew what to expect ive been told so many different things for the foundation and everyone has their own opinion foundations are a nightmare will be glad when their finished rest of house will be a breeze lol:roll:

Just keep in mind that as the O/B you are responsible for the building and if you sell it before the warranty period runs out, you have to cover it for the new owner (7 years in NSW). A lot of this engineering stuff is just to cover yourself in the event of something going wrong down the track. Make sure that anything structural is ultimately certified by someone qualified to do so. If you're working off span tables for floor framing or whatever, you're covered by the manufacturer - but if you're queried on your footings "the architect had a yak with the engineer" might not have any legal standing. It needs to be on paper and signed by someone with a license number or whatever.

For example, we had to make a bit of a change to the footings from the original engineering detail. I paid him $200 to come out and inspect it and write me a letter saying the change was acceptable. That goes in the file with the original details and covers me in case something goes wrong. Stops him being able to say "that's not how I specified it".

People don't think things will go wrong and it's all nice and rosy with architects etc saying "she'll be right" until you have to go back to them and say "you stuffed up". Just something to keep in mind.

Unfortunately this often results in things being over-engineered to cover people's bums - but that's better than the opposite, which is what used to happen - under-engineering to save money. It's a bit like insurance, you might hate paying up front but you'll be glad you did if you ever have a problem.

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Originally Posted by silentC

Just keep in mind that as the O/B you are responsible for the building and if you sell it before the warranty period runs out, you have to cover it for the new owner (7 years in NSW). A lot of this engineering stuff is just to cover yourself in the event of something going wrong down the track. Make sure that anything structural is ultimately certified by someone qualified to do so. If you're working off span tables for floor framing or whatever, you're covered by the manufacturer - but if you're queried on your footings "the architect had a yak with the engineer" might not have any legal standing. It needs to be on paper and signed by someone with a license number or whatever.

For example, we had to make a bit of a change to the footings from the original engineering detail. I paid him $200 to come out and inspect it and write me a letter saying the change was acceptable. That goes in the file with the original details and covers me in case something goes wrong. Stops him being able to say "that's not how I specified it".

People don't think things will go wrong and it's all nice and rosy with architects etc saying "she'll be right" until you have to go back to them and say "you stuffed up". Just something to keep in mind.

Unfortunately this often results in things being over-engineered to cover people's bums - but that's better than the opposite, which is what used to happen - under-engineering to save money. It's a bit like insurance, you might hate paying up front but you'll be glad you did if you ever have a problem.

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thx for that i totally agree which is why were doing 1500 x1400 between piers using timber frame with al cladd and tin roof so way under the max allowable in the asa a little more money and time but the foundations need to be solid and 1800 spans can cause springy floors and problems later we plan on selling in 6mths after completion so we dont want problems coming up when a little more time and effort now at development stage could save heaps of future grief thx for your advice

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Originally Posted by silentC

$200 per cube is about right.

We did an O/B job too and half of it is on brick piers, reactive clay soil.

The engineer's design included specs for brick pier footings. I'd suggest you hire an engineer - as it will make a lot of these things easier for you. You can design some things off span tables but I had engineering detail for strip footings, pier footings, retaining walls and bracing/tie-down for the frame. Cost me about $1800 but covered my backside and removed the guess work.

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wouldnt it be cheaper to use bags of cement and do it ourselves with a mixer.i just worked out about 2500 for the concrete truck surely bags would be cheaper time isnt a problerm as we dont have enough to finish the house anyway so the longer it takes the more money we will have.

It's not really that much cheaper. A cubic metre of sand and gravel premix is about $80 and bags of cement about $6 each. You need 16 to make a cubic metre, so that's $96 + $80 = $176. Then you have to mix it yourself in small loads and it will take you forever. With the mini mix or whatever you use, you can tell them what MPA you need, it will turn up already mixed and you pour it in the holes. I reckon it's more than worth the $400 or so you will save.

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Originally Posted by silentC

It's not really that much cheaper. A cubic metre of sand and gravel premix is about $80 and bags of cement about $6 each. You need 16 to make a cubic metre, so that's $96 + $80 = $176. Then you have to mix it yourself in small loads and it will take you forever. With the mini mix or whatever you use, you can tell them what MPA you need, it will turn up already mixed and you pour it in the holes. I reckon it's more than worth the $400 or so you will save.

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Which is all fine if there is a concrete plant close by.


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See above: $182.00 +gst per cubic mtr of concrete delivered 30km one way

Which is cheap. I have to pay about $220 and I can see the plant from my front door.

ok just spoke to the building inspecter he dosnt know anything about brick piers he wasnt even sure what bricks we had to use i had to explain how to tie down the bearers to the piers i think were in trouble i was hoping he could direct us down the right path.we just want the cheapest way to do the foundations we dont care how long it takes and were willing to work like dogs to do it but its been very frustrating trying to figure it out.i know a few people have said youll only save 400-500 but if thats how much we save then we have to do it as that 400-500 will pay for something else.the budget on this house is ridiculosly tight in fact its non existent practically so any small saving we need.hard work never killed anyone did it??? my hubby would say yes he wants a slab but he also dosnt want to face reality.maybe we should sell the land and go buy another dump and renovate again!!!!!!!!! nah we have to build we just have to figure out what way to do the foundations arghhhhhhhh:~:~:~:~

Personally I think you are setting yourself up for failure.

What you are taking on is a huge task with major and long running consequences, and you're doing it, as far as I can tell, with no experience and no direction. You can't rely on the forum to tell you how to build a house. There are literally hundreds of decisions you're going to have to make during the course of building - you have to make them on the spot and you will have to live with your decisions. If you make the wrong choice, it can end up costing you more money at best or having the whole place condemned and you liable for it at the worst.

Since you're intending to build a house and sell it straight away, my recommendation is that you approach a builder who is prepared to help you out under your owner builder permit and work on a 'consulting' basis. That way you can at least take advantage of his experience, even if you do most of the slog yourselves.

I can't think of a kind way to put this but I think you are completely unprepared to build a house and I for one would not touch it with a ten foot pole when it comes up for sale.

Maybe your best option would be to sell the land and walk away before you get yourself in too deep.

Don't take this the wrong way, I think building a house is a great experience but I think you will get yourself into serious trouble if you proceed on your current trajectory.

One option for you might be a kit home.

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Originally Posted by silentC

One option for you might be a kit home.

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yeah looked into that but too much this time round.i just rang boral to see what bricks to use and they said any of them would be suitable as their all compressed now anyway so they can stand the load of a tin roof and cladding so im just going to go with it and suffer consequences later if any come up.my point is they use them on the load bearing walls in alot of places then use timber stumps to fill in middle so ill just use them for the whole job a bit overkill but itll be strong and looks like our cheapest option just a hell of alot more work lol

Your building brick piers to take bearers under the house? I skimmed through and think I saw that.

Why didn't you say piers to support floor. I though you were talking about freaking piers to take a roof or fence :)

Get yourself some 225mm or 300mm plastic pipe storm water? The cheapest you can find.

Dig hole with post hole digger. Push in pipe. Mark all pipes from a datum (determined height) cut off with hand saw so they are all same height. fill with concrete.

Stud frame is lighter than internal brick so shouldn't be too bad.

Ask an engineer to write you a detail for that.
Depending on the soil will depend how deep you go with the pipe piers to take the bearers. It will also determine the centres you will place them.

You will need to put all thread down the centre of them to bolt to the bearers

Alternatively you could lay footing and put pipes then fill with concrete with rods up centre.

In that case mix the concrete yourself for pipe piers.

Place Alcor over piers as ant caps.

Paint Bitcote or Pabcote over top of piers to reduce damp.

White ants don't like bitumen either.

Footings will be N25 concrete

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Originally Posted by bingoshelley

snip...
we plan on selling in 6mths after completion so we dont want problems coming up when a little more time and effort now at development stage could save heaps of future grief thx for your advice

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you probably don't want to hear this but you're plan casts you as the original builder.
you are on reactive clay
you remain liable for defects for some considerable time (read many years) after you sell the house

If I bought it and discovered a defect I'd pursue for every cent you had or might get in the future to fix the defect.

it sounds as though the only building experience you have is a redimentary at best

think very very carefully about not getting proper and properly documented advice for all aspects of the proposed building.

you could engender a defect by something as seemingly trivial as not properly vibrating the concrete in your piers — a significant risk if you mix the concrete yourself
AND if you do mix yourself how do you demonstrate compliance with the engineer's strength spec?



ian

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Originally Posted by autogenous

Footings will be N25 concrete

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Auto, what do you mean by N25 ?

Tools

25 MPA concrete.

If their intending on owner building then selling 6 months later its a pointless exercise.

A you cant sell within a 6 year period I think. If you do you will need indemnity insurance to cover the period of say 7 years structural guarantee depending on the state.

Building spec homes as an owner builder isn't a really viable thing when you have those concerns.

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Originally Posted by autogenous

Your building brick piers to take bearers under the house? I skimmed through and think I saw that.

Why didn't you say piers to support floor. I though you were talking about freaking piers to take a roof or fence :)

Get yourself some 225mm or 300mm plastic pipe storm water? The cheapest you can find.

Dig hole with post hole digger. Push in pipe. Mark all pipes from a datum (determined height) cut off with hand saw so they are all same height. fill with concrete.

Stud frame is lighter than internal brick so shouldn't be too bad.

Ask an engineer to write you a detail for that.
Depending on the soil will depend how deep you go with the pipe piers to take the bearers. It will also determine the centres you will place them.

You will need to put all thread down the centre of them to bolt to the bearers

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hi autogenius they sound very cheap to do but are they safe they sound flimsy and im more comfortable using bricks as they seem pretty strong.

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Originally Posted by ian

you probably don't want to hear this but you're plan casts you as the original builder.
you are on reactive clay
you remain liable for defects for some considerable time (read many years) after you sell the house

If I bought it and discovered a defect I'd pursue for every cent you had or might get in the future to fix the defect.

it sounds as though the only building experience you have is a redimentary at best

think very very carefully about not getting proper and properly documented advice for all aspects of the proposed building.

you could engender a defect by something as seemingly trivial as not properly vibrating the concrete in your piers — a significant risk if you mix the concrete yourself
AND if you do mix yourself how do you demonstrate compliance with the engineer's strength spec?



ian

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we have no intention of building a house that isnt safe or will require fixing in the next several years it will be built to last the 50 yrs houses are meant to last.there are a lot of houses built on brick piers in reactive clay soil its just that due to cost and time(mainly) they choose to put brick piers on the outer edges and not in the middle i assumed by doing brick piers everywhere then it would be a more stable house.the pier placings are at 1500 down one side and 1400 down the other do you think this would be insufficent??

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Originally Posted by autogenous

25 MPA concrete.

If their intending on owner building then selling 6 months later its a pointless exercise.

A you cant sell within a 6 year period I think. If you do you will need indemnity insurance to cover the period of say 7 years structural guarantee depending on the state.

Building spec homes as an owner builder isn't a really viable thing when you have those concerns.

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i dont think owner building to sell is pointless as you only have to live in it for 3mths to legally avoid paying capital gains tax but you cant sell within the first 6 mths as the insurance company will only cover us for 6 1/2 yrs and this insurance has been quoted at $900 by 3 different insurance agencies.as for building spec homes well we live 100+ kms from spec home builders the builders we do have up here have quoted us 250k to build a 15mtr x 8.4 mtr house with 1.8mtr front verandah and 2.4mtr back verandah.weve worked it out at 80k doing everything we can and are allowed to do by law.we have already been offered 195k for the house when its complete so a waste of time i think not.