[misc_work] Operation Super Shed

[welshpug 1,620]

I remember you saying that the driveway sloped away from the garage, enough to install a drain in the pit that'll run out towards the road?

 

That'd be my only concern with a pit

 

 

no experience of building one though sorry, only of using a 55 foot long commercial pit at my last full time job

[Atari Boy 11]

Nige on northloop.co.uk built a garage including a pit, there was a hugh thread on it, he used fibreglass as the liner iirc.

I can post a link to it now bacause I am using a phone, but let me know if it would help and I will dig it out.

Great project btw.

[M@tt 77]

WP no that isn't really possible unfortunately

 

Cheers Atariboy i'll get registered on there and have a look. I did find quite a few posts mentioning those GRP liners when i googled but tbh i think they're about £1k+ for a decent sized one!!

 

I had a quick measure up this morning and i'd probably need the pit to be 3.7m long x 1 m wide x 1.7m high so i think the hollow block, rebar concrete infill and DPM will probably work out cheapest to do

[Tom Fenton 1,519]

Matt I don't think you'll keep it dry just with visqueen. You really need a liner of some sort. Also your plan sounds good, but as soon as you dig any sort of decent sized depth hole, it will most likely just fill up with bloody water!

 

Having worked with a mate quite a lot in a garage with a pit I can honestly say we never really found it that useful. The only job it was good for was fitting exhausts. Anything else needs the car raised to get weight off the suspension, or wheels off to get to brakes etc, which you then can't do as the jack will fall in the pit!

 

Only rider I would say, was that if you had a proper jacking beam over a pit then that would be useful. But personally from my experiences I wouldn't want a pit in any garage of mine.

[M@tt 77]

jacking beam - check. I'll add it to the list

 

i don't think the water table can be too high where we are both nextdoors have basements and as i mentioned next door also has a pit already so its got to be possible to build one fairly easily!! famous last words

[Tom Fenton 1,519]

Famous last words indeed.

 

And by jacking beam, I mean a proper jacking beam. Not made of wood.

[M@tt 77]

wood its the new steel

[Batfink 201]

My mums garage has a pit and I used to use it for oil changes, but to be honest I found it quicker to just jack the car up and slide under on a inspection creeper thing...

[Peetypug 5]

you will need to shutter the sides before building the blockwork/pouring the concrete base, otherwise you will end up having the side falling in on you while working on it

also H&S says anything over 1 meter high needs shuttering to stop it falling in/crushing you

 

if the ground is solid enough then you shouldnt need to put a base down

 

when i worked on building a dairy pit we used visqueen just for the base and then used a type of tar that sealed the blocks from the outside, you wont have this option due to lack of room around it

try using 2 layers of it instead

 

also, tie the steel rods that you will be putting in the blocks to the steal you use in the base

 

on a final note, make it slope slightly to one end and have a catchpit for any water that may get in

 

you could use a fish tank pump to pump the water out (a romote one not submergable (spelling) )

[Atari Boy 11]

M@tt, this is the thread I was talking about, well worth a read.

[MrG 3]

As Pete says line it with some sort of thick (1200gge) visqueen layer, but try and encase the whole pit with one sheet. You'll need to then carry on this visqueen sheet out to the external wall construction to ensure any moisture doesn't get around the edge and leak in. You can then lap it up the new external wall to form a complete DPC.

 

Best lay this layer onto a bed of sand (about 50mm) as that'll stop it puncturing, then once happy with it pour about 100mm of concrete. But you will need it to be shuttered in order to keep it all in check. Place the visqueen against a layer of MR ply on the vertical faces then pour concrete between this and the shuttering. If you need to join the visqueen, overlap it by about 150mm min.

 

It'll be a lot easier if you don't have a pit though! Just run the visqueen beneath the concrete floor and you're done.

 

You could lay it to fall, but the idea is to not allow water in in the first place.

 

Have fun.

[M@tt 77]

Cheers chaps!

 

i had a read of that thread on Northloop that was really useful cheers!

 

MrG so if i've read that right you're saying

1) dig the hole

2) put 50mm of sand on the floor of the pit

3) line the pit with the visqueen

4) build a shutter frame and place this directly onto the visqueen in the bottom of the pit and pour the concrete base in

5) remove the shuttering

6) build the hollow brick wall - Q: is it best to build a few courses high then back fill between the visqueen and the edge of the hole with concrete as i go or do it all at the end once the walls have been completely finished?

7) Q: do i need something between the outside edge of the hollow brick wall and the visqueen before back filling? or is the visqueen ok up against the hollow brick surface?

 

Due to the pit size i don't think it will be doable in a single sheet of visqueen, they only seem to come in 4m wide sheets of varying lengths and with the pit needing to be about 1.8m deep and a meter and a bit wide a single sheet wont cover it so i'll have to join it. I've bought a 15mx4m sheet of 1200gge visqueen and some jointing tape so i should be good on that front.

 

I was having a look at the hole and realised its way too big to attempt by hand! so have looked into mini digger hire prices. You seem to be able to rent a digger for the day at 80+vat delivered and collected or I've been quoted man and digger £150 for the day. I put an ad on the local Sheffield forum saying man and mini digger wanted to dig hole for what i said was probably about half a days work i got several quotes for £250!!! . £500 a day not bad!!! they can jog on!! I'm just debating whether to pay the extra £50 and get the pro in who will probably get it done in half the time it would take me at not destroy any other part of my house or accidentally drive the digger into the hole!

Edited March 19, 2010 by M@tt

[welshpug 1,620]

man + digger for hire tend to be slightly larger ones around the 3.5t that you need a licence/card for, need a much heavier trailer, and you're also paying for the guys time hence the higher cost.

 

They'll be able to do the job a hell of a lot quicker than a guy with a 1ton digger!

 

also the guys that do this for a job will be able to advise on how to do it more often than not.

Edited March 19, 2010 by welshpug

[M@tt 77]

no i said the job was for a man + mini digger due to location, some builders are just money grabbing, overcharging tw@ts!!!

[Peetypug 5]

you want a jcb micro type machine

they can fit throough your front door they are that small (i know you dont need it to do that)

 

anyway, the last one i hired cost me £90, dropped off lunch time friday, picked up lunch time monday

ring round a few places first (try to get them to include fuel)

[MrG 3]

OK so you're putting a blockwork inner skin into the pit are you? If so you can either dig the hole, put the sand at the base (to stop the visqueen being punctured) then put the visqueen in, now you need to make the pit water tight so try and avoid any joins in the pit itself, if you have to tape and joint it really well otherwise water will seep in, and have a lap of around 150mm min where ever possible, then pour the concrete into the base with around 100 to 150mm covering, preferably reinforced but that's not completely necessary.

Once cured you can either shutter the sides out leaving a gap of around 100mm between the visqueen and the shuttering, then pour the concrete down into the gap, preferably reinforced as well. Or build a blockwork wall and use this blockwork wall as the shutter and either pour concrete between the two as before or build the blockwork directly up against the visqueen layer. You can also protect the blockwork edge facing the visqueen with a product called RIW, basically a horrid tar/bitumen substance but this seals everything it touches. But ruins clothes and brushes etc.

 

But think of it logically and think of a water tight bag, that's what you're trying to achieve.

 

How bigs the pit going to be? 15x4 should be good if you're going to have a pit of around say 800 deep and 800 wide, this will allow you to line the pit without any joins inside and then have good lapping to join onto a layer that you could install under the main garage floor.

 

I have a pdf dwg if you wish of a method with or without blockwork to the pit if that's any easier, pm me your email and I'll send it over.

[M@tt 77]

this is what i'm kind of invisaging

 

 

right another bit of advice required

 

i'm going to have the outside clad in "Waney Edge/Lap" planks like so, to keep the rustic feel of the property

 

 

however the planks are cut "green" and are prone to a bit of shrinkage over time. The new building is going to be 10m in length and the planks aren't available in that length so i'll have to use shorter lengths, my slight worry is that as the planks shrink slightly, small gaps will appear where the ends of the plank once butted up to one another. I'm therefore wondering whether its necessary to cover the wall frames in some sort of water proof membrane before adding the cladding, so that if small gaps do appear, the insulation doesn't become wet etc. i'm thinking something like roofing sheet membrane.

 

Any experience, suggestions, comments?

Edited March 19, 2010 by M@tt

[miamichris 9]

right another bit of advice required

 

i'm going to have the outside clad in "Waney Edge/Lap" planks like so, to keep the rustic feel of the property

 

 

however the planks are cut "green" and are prone to a bit of shrinkage over time. The new building is going to be 10m in length and the planks aren't available in that length so i'll have to use shorter lengths, my slight worry is that as the planks shrink slightly, small gaps will appear where the ends of the plank once butted up to one another. I'm therefore wondering whether its necessary to cover the wall frames in some sort of water proof membrane before adding the cladding, so that if small gaps do appear, the insulation doesn't become wet etc. i'm thinking something like roofing sheet membrane.

 

Any experience, suggestions, comments?

 

Sorry I haven't put anything into this topic yet mate, been moving house and had no internet for a while.

 

Personally, I wouldn't be cladding the building in green timber as there will be loads of movement in the timber over time, I would be looking at something more like a tanalised tongue and groove cladding, not exactly rustic I know though! You can get cladding for log cabins etc that looks more rustic, try a local shed builders and see what types of cladding they have?

 

I know what you mean about the lengths not spanning the whole 10m of your building, typically I would splice the lengths together so that the end of each board is mitred into the next, creating an overlap like this:

 

----board 1-------//-------board 2-----

 

If that makes sense? It will be trickier to do with those waney edged things though!

 

Is the building timber framed then? If it is I would use a membrane like Tyvek http://construction.tyvek.co.uk/Tyvek_Cons...wall/index.html on the outside of the timber walls, then counter batten it with 2x1" roofing lathes to give you an airflow space and then nail your cladding to the counter battens, like this:

 

l Timber frame ll Tyvek ll 2x1" battens ll Cladding l

 

If that makes sense, its hard to draw on the computer!

 

Hope that helps

[Henry Yorke 269 3 Cars]

Is this a garage / workshop or a hunting lodge with a built in underground abattoir!!

 

Tanalised would be the best for its waterproof properties though it is more expensive and can look quite green. However I am guessing standard plans with creosote / fence preservative would suffice.

 

I would run trellis up the side of it with some plants to help blend it in better, however it is a north west facing wall on the long side so not that sunny.

[M@tt 77]

Cheers for the info Chris. I know what you’re saying about the tongue and groove but I think I’m going to go with the waney edge purely for the aesthetics . I'll get some of that Tyvek stuff though as that looks spot on.

 

A bit more progress this weekend....

 

My next door neighbour has kindly let me store my dismantled CTI on their drive for as long as I need, so the first job was to rebuilt the suspension and put it back on its wheels so that I had a rolling shell. With that done myself and Mike pushed it off my drive and onto his. With that done I could turn my attention to some of the ground work that needs doing.

 

I chased out the existing power cable between the house and the drive. This is going to be replaced with some 6mm 3 core SWA.

 

 

Nothing is ever straight forward is it?? I'm going to block pave the section in front of the garage so I needed to cut some of the large stones at the base of the wall so that the bocks can sit up against the edge of the wall. However I came upon this mother!!!

 

 

It took multiple passes with a 9", sledge hammer and a SDS drill to get rid of it!!

 

I also had to cut down another large stone so that it was in line with the rest of the other cobbles

 

 

The drive was covered in limestone chippings which I’m not going to need so I piled them all up in the hope I can get someone to come and take them away rather than having to pay for a skip to put it all in. Any takers??

 

 

With them all removed it left me with this

 

 

 

So I’m slowly making progress

Edited March 21, 2010 by M@tt

[Atari Boy 11]

Great progress M@tt.

[M@tt 77]

right....

 

Matt what are you doing about roof trusses? i hear you all cry! well that's a very good question!!

 

Basically the roof needs to be as lightweight as possible due to some of the weight being supported on the dry stone walls (even though they're pretty substantial and I've had no problems with the current structure),but also needs to be strong enough to support my weight whilst i felt or shingle it (still to be decided) but its not going to be walked on etc regularly so it doesn't need to be overkill in the structural design. I'm going to go with 3"x 2" CLS for the truss frames with with 12mm OSB or plyboards for the roof sheets

 

Therefore I've come up with this simple truss design. However I'm still undecided as to whether the central vertical support is really needed as ideally without it it will give me a nice single open space to store stuff up in the rafters, although its not the end of the world if it i do need it. The truss sections will be held together with ply gusset plates (blue bits in pic) which will be glued and nailed.

 

As it shows on the diagram the roof will span about 3.5m between the vertical support and I'm aiming for around a 25 degree pitch on the roof

 

 

any thoughts from the builders out there?

Edited March 23, 2010 by M@tt

[Peetypug 5]

I'm looking at some roof trusses right now that are roughly the same size. They have center supports and to be honest I can't say I have ever seen any that haven't had any

But saying that all the roofing we do is tiled

I canSend you a picture but don't have your number on this phone

[Henry Yorke 269 3 Cars]

You've got the tops overlapping. If you angled them so they butted up to each other, you would get a stronger structure and a neater ridge. You may get away with out the centre support, but it is the optimum as it will also help spread the weight of anything you put in the centre if you put a truss onto the lower horizontal joint.

 

The simple but strong design has supports coming down from the long sides. Have a look here http://www.diydoctor.org.uk/project_images...Trusses%201.jpg

[miamichris 9]

right....

 

Matt what are you doing about roof trusses? i hear you all cry! well that's a very good question!!

 

Basically the roof needs to be as lightweight as possible due to some of the weight being supported on the dry stone walls (even though they're pretty substantial and I've had no problems with the current structure),but also needs to be strong enough to support my weight whilst i felt or shingle it (still to be decided) but its not going to be walked on etc regularly so it doesn't need to be overkill in the structural design. I'm going to go with 3"x 2" CLS for the truss frames with with 12mm OSB or plyboards for the roof sheets

 

Therefore I've come up with this simple truss design. However I'm still undecided as to whether the central vertical support is really needed as ideally without it it will give me a nice single open space to store stuff up in the rafters, although its not the end of the world if it i do need it. The truss sections will be held together with ply gusset plates (blue bits in pic) which will be glued and nailed.

 

As it shows on the diagram the roof will span about 3.5m between the vertical support and I'm aiming for around a 25 degree pitch on the roof

 

 

any thoughts from the builders out there?

 

this is one for me I think!

 

I would just do a "cut roof" instead of trusses. A ridge board running the full length of the building at the top where the two plumb cuts of the rafters meet and are screwed/nailed to it, then a 4x2" wall plate fixed on top of your walls and your rafters have a "bird's mouth" cut to allow them to sit over the wall plate and be nailed/screwed in place. The overhang from your rafters will create a soffit/eaves space and then you have another plumb cut on the bottom of the rafter, where your fascia board will be fixed on to.

 

The horizontal piece between the two rafters, called your "collar tie" can be lifted up to nearer the top of your rafters to give you a higher ceiling. Sounds a bit confusing probably, done a quick diagram to show you what I mean in Paint, its a bit gash though!

 

 

The ridge board is sticking up in that picture but it should be flush with the top of where the two rafters meet, I just cant be arsed to change it now

 

I'll sketch you something more detailed up tomorrow and scan it in, I can't draw on the computer!

 

Timber dimensions, I'd beef your rafters up a bit to 5x1 1/2" rough timber , the collar ties you could get away with 3x2" unless you want to store stuff up there, if so beef them up a bit too. Ridge board is normally about 8x1" PAR timber I think and wall plate is 4x2". 1/2" ply will do rightly for sheeting the roof if you're going to felt it, get 1/2" felting nails though or they'll stick through underneath!

 

Easiest way to do it is put a couple of sheets of ply down on the ground and draw it out full size, then once you get one rafter cut and the plumb cuts/bird's mouth are right you use this as a template and cut all the others the same