Garage Workshop Subsidence

[Barnaby WildeParticipant @barnabywilde70941]

Since I moved in 15yrs ago I have been living in denial of the small crack slowly growing into a HUGE crack down my garage workshop wall. I know a bit about general building & the thought & cost of demolishing it & re-building on a more solid foundation has been nawing away at me for some time.

It's never going to fix itself is it? So I just screwed an 8'X4' ply board over it & called it a tool rack

I've had builders look at it over the years, some say do it on insurance & some say "don't ever mention subsidence to your insurance co'", which makes a lot of sense, and prices have been mentioned in the £10-£15k range.

Last Sun lunch, I just happened to be telling my tale of woe to the lads down t'pub when one old chap slammed his pint down & said "thas not got subsidence, I knows cos I built t'damn thing & now'ts moved round ere since blitz.

So he popped round yesterday & I could've hugged him. Rather than the foundations sinking down they're actually bulging out. He spotted it instantly, apparently the concrete slab was laid to take the weight of a car spread across 4 wheels & NOT a 1.5t lathe + 1t milling machine up by the back wall

He reckons that the weight concentrated at one end + any vibration over the years has slowly compacted the aggregate under the slab & pushed the foundation out just enough to cause the crack. Simply cut out half the slab, sort out the aggregate & re-lay a thicker slab at that end.

Phew, saved me £10k at least

[Barnaby WildeParticipant @barnabywilde70941]

[Brian WoodParticipant @brianwood45127]

Hello Mick,

What a happy ending, surely worth a Boxing Day bonus to the old chap in the pub.

I guess you live in Yorkshire too, how do I know!

Regards

Brian

[larry PhelanParticipant @larryphelan54019]

Just goes to prove the old saying;

"There,s only two ways to do a job,

A Call in the experts

or

B Get someone who knows what they,re talking about. !!

[Tractor manParticipant @tractorman]

So has the slab cracked and split? Not sure how the wall foundations can have been affected if the slab is intact.
And not sure how the fix will work, wontvthe wall need supporting if you’re going to cut the slab out?

[Sam Longley 1Participant @samlongley1]

How much has the floor settled?

how far has the wall bowed out

What is the construction of the wall?

[Barnaby WildeParticipant @barnabywilde70941]

Amazingly the slab itself hasn't cracked, which is a testament to it's strength. I'd never noticed it before because none of it is very visible but the floor at the rear end is a good half a brick lower than when it was laid.

The slab was laid inside 6 course of bricks laid on top of the poured concrete foundation. At the rear of the garage It simply floats on top of the aggregate that was back filled into the foundation. The chap pointed out that the back fill is deeper than it should be because the garage is built to the entrance level at the front, making it 2' deep at the rear. Over time, the weight & vibration of the lathe & mill has caused the slab to compress the aggregate & there's nowhere for it to go except to bulge those 6 courses outwards.

We didn't, but he guarantees that when a test hole is dug at the rear we will see the 6 course of brickwork bulging out.

Once the backfill is redone with a little more compaction & the slab re-laid, he reckons cutting into the mortar horizontally along the back wall will see the crack close itself as the bricks are relieved of the pressure. Or something along those lines, all I heard was the £cost difference between that & demolishing then re-building.

[Neil WyattModerator @neilwyatt]

I was at a talk today.

Someone found asbestos in a solid bund along a river.

Panic! Asbestos! It must be got rid of! It was going to cost £2.5M to cap it with concrete.

A second opinion was sought and it cost £100K to carry out details site investigations and see how plentiful and mobile the asbestos actually was.

Result was that as long as the bund was left vegetated so the wind couldn't pick up dry soil, the asbestos wasn't going anywhere.

Taxpayer saving £2.4M

Neil

[larry PhelanParticipant @larryphelan54019]

Interesting !!!

[duncan webster 1Participant @duncanwebster1]

friend of mine's widow was advised that the asbestos ceiling of his basement workshop would have to be removed at huge cost. I contacted council building inspector who went away, took some advise and rang me back to say that we should get it sprayed with paint to immobilise any loose fibres and forget about it, so to amplify Larry's comment, get someone who knows about it AND doesn't have a financial stake in choosing the most expensive option

[SamsarandaParticipant @samsaranda]

The comment on the “asbestos” bund brought to mind a situation that occurred when I was a governor at our village primary school. The school was undergoing a £2 million plus, rebuilding and extension, while the school was being used. During the planning stage it was found that the site during the 19th century had hosted a brickworks which meant it was deemed a contanimated site because of heavy metals etc. The development budget could not stand the huge cost involved if soil from excavations had to be disposed of off site as it would be deemed contaminated waste needing expensive disposal. The solution, bulldoze the excavated soil to the edge of the site and make a large bund surrounding the site and cover with an impervious membrane, to date I am not aware of any monitoring having been carried out to ensure no leakage of contamination.

Dave W

[peak4Participant @peak4]

Also you could investigate a wall crack repair kit when you come to re-pointing. Other makes are available, and  in different diameters.

Not tried one of these myself, but used a similar method to tie inner and outer skins of a wall together.

 

Bill

Edited By peak4 on 23/02/2018 00:08:05

[mark costello 1Participant @markcostello1]

Inlaws have several out buildings covered in asbestos. Absolutly terrifying considering I used to mill, turn and band saw it with no protection before it turned deadly.

[SamsarandaParticipant @samsaranda]

Mark, was there a point in time when asbestos suddenly turned deadly? Only joking we all know what you mean. Dave W

[Barnaby WildeParticipant @barnabywilde70941]

Asbestos was deadly from the very first moment it was discovered, just like radium & countless other substances.

How we deal with the knowledge is what judges us. How did we deal with the knowledge that this ground breaking substance that promised to revolutionise our lives, but actually served only to kill us all slowly?

I don't know & I can never understand how my garage / workshop subsidence turned from saving a few £1000quids into a discussion on asbestos, & now it includes radium too !

I'm told that talcum powder is the next BIG one . . . When they finally allow the whole story to break.

[MeunierParticipant @meunier]

Posted by Mick Charity on 23/02/2018 19:40:49:

snip / I don't know & I can never understand how my garage / workshop subsidence turned from saving a few £1000quids into a discussion on asbestos, & now it includes radium too ! /snip

There are times when any attempt at rationalisation is futile, some of those OT moments can be educational though.
DaveD

[Neil WyattModerator @neilwyatt]

Posted by Mick Charity on 23/02/2018 19:40:49:

I don't know & I can never understand how my garage / workshop subsidence turned from saving a few £1000quids into a discussion on asbestos, & now it includes radium too !

It was my example of how another expensive knee-jerk solution was rationalised with knowledgable advice.

Neil

[brickyParticipant @bricky]

If the concrete is being relaid and the hardcore is 2' deep remove the hardcore and relay it in 4" layers compacted.It is not sensible to relay concrete without doing this as the hardcore will keep sinking down.In the drought of 1976 whole floors left the skirting in properties built on clay which dried out and shrank letting the concrete sink. hardcore was tipped in without compacting in layers before this date and the regulations were changed after this.

Another ancient builder Frank

[mark costello 1Participant @markcostello1]

Sometimes the best parts of these posts are when it goes down a different path. Not slighting Anyone. Just an unexpected dessert.

[Nick HughesParticipant @nickhughes97026]

You could also look into having the sub base Pressure Grouted to stabalise and strengthen it.

[alan ord 2Participant @alanord2]

Asbestos comes in three forms. Blue asbestos, Brown asbestos and White/Grey asbestos. They are treated in separate ways. Blue is by far the most dangerous and once confirmed after testing must be removed and only by a specialist companies. I also believe that legally the Environmental Health and Safety Department must be informed. Brown is next and is relatively safe and left alone in situ so long as their is no damage to the surface allowing fibres to escape. Obviously there can be no drilling or modifications to Brown asbestos structures once in place. White / Grey is the least dangerous and most old corrugated roofs are made from this form of asbestos. Incidentally there is a lot of low grade asbestos in older schools and left in place as long as it is untouched. At a place where I worked I was responsible for removing some old large factory heating boilers when we discovered asbestos that, after testing, proved to be Blue. The H & S Inspector shut the building down and the company who removed it shrouded and sealed the whole building in plastic sheeting and to enter you had to go through an air lock with a negative pressure inside the building to prevent asbestos escaping.

[Ian ChildsParticipant @ianchilds37813]

There are 6 forms of asbestos . They can be grouped into amphibole or serpentine groups depending on the chemistry of the rocks they are formed from. The more dangerous is the amphibole type. The white form, chrysotile, is a serpentine form and was previously not considered as dangerous as brown or blue as the fibers are usually shorter and less sharp. I remember being taken to an white asbestos mine (openpit) as a student and picking bits up to take home! incidentally this mine had Europes largest spoil heap at the time. One rare type called erionite, is responsible for many deaths in a village in Turkey and Amosite is an acronym for asbestos mines of South Africa.

[Barnaby WildeParticipant @barnabywilde70941]

There is a substance, a drug if you like, that has caused countless hundreds of thousands of deaths, The origins of its introduction into mainstream society can be traced back to one man & one particular period in history, yet nobody ever talks about it in this way. You could say that this particular man was the biggest mass murderer that history has ever known. Bigger than Lenin, bigger than the Khmer Rouge & bigger even than capitalism itself.

You can spot its addicts from miles away. It kills all of its victims in the end, yet the cause of death is rarely attributed to it.

On average, every household in the western hemisphere has at least 1kg of this substance hidden away somewhere.

It is far more dangerous to our health than blue asbestos fibres blowing in the wind, pure heroin, fast motorcycles or even the hygeine standards of a fast food restaurants kitchen.

We feed this to our children.

99.99% of the population cannot comprehend just how harmfull this substance is.

I'll give you a clue, it isn't salt.

[Michael MallesonParticipant @michaelmalleson22793]

Sugar !

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