Slatted shed question

massey6480

Considering building a new slatted tank in front of existing shed. How close to the existing pillars would i be able to dig for the tank as i would like to go to 8 feet deep and keep as close to the shed as possible.Also would 7x3 h iron be strong enough for a roof truss in a lean to shed . The beam would be 25 feet long but would meet a upright at 16 feet and the rest would be for a over hang

Bizzum

massey6480 wrote: »

Considering building a new slatted tank in front of existing shed. How close to the existing pillars would i be able to dig for the tank as i would like to go to 8 feet deep and keep as close to the shed as possible.Also would 7x3 h iron be strong enough for a roof truss in a lean to shed . The beam would be 25 feet long but would meet a upright at 16 feet and the rest would be for a over hang

My opinion would be that 7"x3" rsj aint beefy enough.
In relation to digging a tank beside an exixting shed: We dug a tank very tight to an existing leanto, but the ground is very very good.

See pic.

blue5000

OP whats the ground like? Go for 8x4 inch pillars, and stay out at least 8 ft from old shed. Just my 2 centsworth.

massey6480

Bizzum wrote: »

My opinion would be that 7"x3" rsj aint beefy enough.
In relation to digging a tank beside an exixting shed: We dug a tank very tight to an existing leanto, but the ground is very very good.

See pic.

Thanks for the reply Bizzum that looks to like it would leave you with about 4 feet between slats and shed thats what i would be hoping for Did ye prop the pillars with any thing

Bizzum

massey6480 wrote: »

Thanks for the reply Bizzum that looks to like it would leave you with about 4 feet between slats and shed thats what i would be hoping for Did ye prop the pillars with any thing

Couple more pic's from roughly the same angle, after a bit of work.

I remember talking about putting in an acro or the like before we dug it but we felt when we dug it would go nowhere. The two end walls would take a lot of the weight I suppose.

vanderbadger

Bizzum wrote: »

Couple more pic's from roughly the same angle, after a bit of work.

I remember talking about putting in an acro or the like before we dug it but we felt when we dug it would go nowhere. The two end walls would take a lot of the weight I suppose.

what size slat is that Bizz, 11"6?
looks like a nice job

tvo

if the ground is relatively good you could go v tight to the pillar if they are propped. Dry weather would be a huge advantage in this case. Would definately use 8x4 or heavier as the beams.

Muckit

Tie in the outside girders of the existing shed to the furthest away ones temporaily using the trusses or uprights you intend to use for the new shed.

Then add a bit of diagonal bracing (both ways in an X). You can't beat a bit of triangulation to keep things from moving

I seen a neighbour dig out a tank to convert an existing loose shed into a slatted shed using above method. Loads of lads have done it without bother. But you can't skip on the bracing. There's strength when everything it tied in together. A single girder out in no man's land has the potential to move.

cjpm

A lot of contractors won't touch the job if there's any risk of the excavation collapsing as they could face massive fines and jail if an accident occured, or hefty fines if their site was inspected.

Legally they have to support the sides of the excavation if it is over 4ft or else batter it back at a slope of 1 is to 1.

A good few will have first hand experence of these incidents and some will have the scars to prove it, i know a fella who was pinned between a collapsed excavation and a shuttering pan, ended up with broken ribs and collar bone.

What often happens with these collapses is that the soil cracks about 3 ft from the edge and a whole block falls in suddenly.... 3ft x 3ft x 3ft block of soil weighs approx 2 tonne.

Just be careful...

Figerty

I've seen this done. By a contractor who was willing to do it. but it was a close call and the adjacent sheds were close to collapse even with bracing.

The problem was that over the years slurry and traffic had softened the ground where the shed was going and it was very dodgy for the lads concreting the tank.

Be very careful, ultimatley if the HSA come knocking you are going to be in serious bother if if goes wrong.

Bitten & Hisses

When I was doing my tank a few years back, we needed to excavate right up against an existing cubicle house. We put a narrow bucket on the digger and dug directly below the poles of the existing shed (as far as we could go with the digger) before we dug the actual hole for the tank. These holes were immediately filled with 35N concrete and left to set for a week or so. We used 7 metres to underpin 4 points on the building. When we excavated the tank, we exposed parts of the concrete supports, which looked as if they had always been there.

locky76

Bizzum i don't measn to offend you (i've enjoyed and respected numerous posts of yours) but you'd be jailed if the HSA inspected during the construction of that tank.
What chance would the person bolting the shuttering have if even a minor slippage of the side of the excavation occured, even worse when they're striking it after vibrating the concrete etc. etc.
As i say i don't mean it to be personal or offensive but with the level of death on Irish farms i think we all bear a degree of responsibility, i knopw i've taken stupid chances down through the years.

Bizzum wrote: »

My opinion would be that 7"x3" rsj aint beefy enough.
In relation to digging a tank beside an exixting shed: We dug a tank very tight to an existing leanto, but the ground is very very good.

See pic.

Tipp Man

locky76 wrote: »

Bizzum i don't measn to offend you (i've enjoyed and respected numerous posts of yours) but you'd be jailed if the HSA inspected during the construction of that tank.
What chance would the person bolting the shuttering have if even a minor slippage of the side of the excavation occured, even worse when they're striking it after vibrating the concrete etc. etc.
As i say i don't mean it to be personal or offensive but with the level of death on Irish farms i think we all bear a degree of responsibility, i knopw i've taken stupid chances down through the years.

isn't that up to the contractor to do - if you hire guys to build a tank then surely it is their responsibility to do so in a safe fashion??

pakalasa

I dug a 4 foot hole in very dry land recently by hand. It fell in on one side.
It does happen regularly, better be safe than sorrow.

David brown

massey6480 wrote: »

Considering building a new slatted tank in front of existing shed. How close to the existing pillars would i be able to dig for the tank as i would like to go to 8 feet deep and keep as close to the shed as possible.Also would 7x3 h iron be strong enough for a roof truss in a lean to shed . The beam would be 25 feet long but would meet a upright at 16 feet and the rest would be for a over hang

we dug tank close to existing pillars by first welding irons to the stanchions and fixing them to the concrete floor. then we dug out the tank and was able to completely undermind the stanchions. when the tank was poured we extended and fixed the stanchions to the tank floor.This resulted in a distance of 2' between edge of slat and stanchion on completion. Soil type and water table has also to be taken into account.
Re 7x3 rafter. check out dept spec for farm buildings S.101.
Note also that all farm buildings has to be done to grant standard regardless of getting grant. Hope this helps.

6480

i ed try and dig the tank and pour it in good weather

1chippy

we put a tank lenghtways across the front of a cubicle house. it finished 2' 6" from the front. dug down into channel and springs. had no issue with subsidence but all it takes is one slip.

Bizzum

vanderbadger wrote: »

what size slat is that Bizz, 11"6?
looks like a nice job

Yeah, 11"6', your on the ball!

locky76 wrote: »

Bizzum i don't measn to offend you (i've enjoyed and respected numerous posts of yours) but you'd be jailed if the HSA inspected during the construction of that tank.
What chance would the person bolting the shuttering have if even a minor slippage of the side of the excavation occured, even worse when they're striking it after vibrating the concrete etc. etc.
As i say i don't mean it to be personal or offensive but with the level of death on Irish farms i think we all bear a degree of responsibility, i knopw i've taken stupid chances down through the years.

No offence taken.
If we were one bit worried about the job being unsafe, perhaps I'd be offended. At no time was we worried. I think the concrete floor in the existing leanto helped stabilise the shed and as I stated from the outset the ground is very good. We would have a lot of experience in the area too. That tank was dug out in Aug 08, when that serious rain fell and still not a bit of slippage.
There was mininal work (if any) done between the shuttering and the excavation face as the shuttering was dropped down in sections and the tank poured in 2 halves.
We would take safety very serious and would not be behind the door reminding anyone doing work for us of our approach to safety.

I would urge anyone taking on a job like this to spare nothing trying to be safe, and take no shortcuts.