Resurrecting a Portakabin

[awemawson]

When we moved here eleven years ago we inherited two Portakabins, an 18 footer and a 20 footer. Both had been used as kennels as the previous owners trained Greyhounds, both had been clad it Shiplap to disguise them, and both were in pretty horrid condition with leaking roofs.

The 20 footer got a new floor, the roof covered in hot laid roofing felt and the wife adopted it as a potting shed / farm cat housing / small mower and tools store.

The 18 footer had never been properly levelled, but I stored construction tools in it, spare tractor wheels etc, and a few years ago fibre glassed the leaking roof. It also houses my Hydrovane compressor to keep the noise out of the workshop. Fibre glassing had proved a bit of a disaster - I had started the job on an overcast day, carefully measuring the roof temperature and applied the correct ratio of catalyst. It started off well, but when I was about 2/3rds done the sun came out, the roof warmed up and the resin set before I could properly get it down  It looked a mess but it actually stopped the leak 

Last year the leak came back - just a little drip. Now one of my tenants on the farm is a builder who occasionally fibre glasses roofs, and he volunteered his man to re-do it. This was NOT a good idea - what had been a minor leak turned into a major torrent so something obviously needed doing. Replacing The Portakabin sounded a good idea, but when the logistics of  moving a replacement here, and more importantly disposing of the old one were taken into account it would have been a very expensive exercise.

Then I had a flash of inspiration - if corrugated roofing sheets can be curved to form Pig Arks, they should be able to curve some for me so that they just over span the width of the Portakabin. So discussions took place with Southern Sheeting, and the outcome was I've ordered six curved sheets that span 10 foot and a rise of 12" which gives about 6" overhang to keep water off the walls. Delivery about 2-4 weeks.

So in the mean time I need to work out how to level the Portakabin.

This brings me to this morning. The last expectant Ewes are hanging on to their lambs so nothing to do there - can't finish the chicken shed as the cladding hasn't arrived, so use the time at least measuring how big the problem is - certainly the tilt is sufficient for things to roll on the floor 

Now the obvious measuring tool is my Spectra Physics rotating laser level, and equally obviously what needs measuring is the top of the four jack legs as they are fixed to the structure of the building and should be fairly stable whereas the floor is somewhat wavy in places - probably something to do with the four tons of sandblasting grit I had in there at one time 

OK the laser sits on a tripod, the resulting swept beam needs to be above the Portakabin roof - tripod too short by a long way. Need a suitable 'something' to put it on. My Diesel Bowser proved up to the job - just had to clamp a bit of heavy angle to it to stop one leg slipping off.

So a few pictures of the issues

[awemawson]

Usually you would mount the sensor for the laser level on an extending surveyors pole - but I find that a bit of 2x1 lath is easier in this sort of situation, and you can write on the wood to preserve the measurements.

Once the laser was levelled (that was fun balancing on the tank and not disturbing the tripod  ) it was a simple matter of holding the lath against each of the four Jack Leg tops and drawing a pencil line.

This has allowed me to draw up a plan of the four jack legs showing how they vary in height. 4" from highest to lowest but the jack legs are 48" from the ends of the structure so if you do the maths this equates to over 7" in the 18 foot of the Portakabin. Some trains would struggle up that incline 

Next job - work out how to get at the two jack legs that are obstructed - probably involve removing planks from the fencing - better not do that today - expecting 60 or so guests tomorrow for our fund raiser tea for the Hospice - be in trouble if I make a mess !

[Jo]

SNAP   

I put corrugated iron on the top of my old porkie bin about 20 years ago. Jacked up on the front of the roof with a bit of 4 by 2 and a couple of supports. The sheets were just big enough to over hang front and back of my 20ft by 10ft Porkie. The birds think the holes (wobbles caused by the corrugations ) are wonderful I always have them nesting under there every year (not sure if the youngsters get toasted when it gets really hot  ) Wood cladding does make them look a little more shed like 

Looks like you still have the original hardboard ceiling with the wafer of fiberglass above it. I took that down and keep promising myself I will put something else back up there

Jo

[awemawson]

Decking up the sides - that should be pretty substantial 

I didn't want to leave a gable end opening - no problem with the birds nesting but the rats would take up residence as this Portakabin is adjacent to the straw and feed store.

[awemawson]

Hanging around this morning waiting for a delivery of cladding for the chicken shed so I thought I'd have a go at exposing the two Jacklegs that are obstructed by overgrown fencing.

Jackleg C was behind an amazing growth of Ivy - one root of which resisted until I gave up trying manually and tucked the bucket of the JBC803 behind it to show who was boss. Even so it resisted for a while !

Jackleg D was far easier - relatively little ivy.

Then is was just a case of removing the feather edge fencing sufficiently to allow me to get at the jacking points. Fortunately I saved some identical fencing from a length I removed years ago - all stacked alternately thick / thin edge and tightly banded to prevent warping - they seem to have survived the ravages of time 

Between the two Portakabins is a roof forming an open fronted store used for the ride on Mower - the roof is 'Onduline' a bitumen felt corrugated and slightly flexible material. As this Portakabin is jacked up the  Onduline is going to have to absorb the movement, although the two sheets nearest the gable end will have to be removed to give access. One sheet has sagged and needs replacing anyway as vegetation has built up on it and water has puddled over the years.

 . . .OK done all that and the cladding is still not here 

 

[wgw]

Portacabins don't last well, I would put a few posts up with the round sheets as a roof, just to keep the rain off the cabins. To late now ,but a good source of rounded sheets for pig arcs etc. is old grain silos.  We have two cabins, flat roofs. These were made for accommodation units on a oil platform yard and are well made. Roof started seeping last year ( only about40 yrs. old ) .By far the cheapest remedy was roof over in steel sheet on 4x2 timbers.

[awemawson]

WGW

 - pig ark sheets are not only too curved, but have insufficient reach - I have a couple here unused at the moment. No grain silos unfortunately - the nearest one has been converted into a letting holiday home 

[awemawson]

Having at long last finished chicken shed #2 this morning I could give serious consideration to jacking up the Portakabin to a more level state.

Jack leg 'B' is the most accessible so I thought that I'd start there - it is also fairly close to the entrance door, and as years back I cast a concrete threshold abutting the doorway I would be able to see if they stuck together or (hopefully) moved independently. However close examination revealed one of those 'gottcha' situations. The cranked pin that pins the inner and outer sliding elements of the jack leg had been put in from the wrong side, so that if the jack were placed where intended, you couldn't remove the pin when the initial weight was taken. A bit of innovative jack placement and application of odd angles of jacking got the pin out and back the right way round and the leg extended by 2" - and the good news was that the threshold concrete stayed put as the cabin moved upwards 

The other legs 'C' and 'D' had the pin the right way round, however the arris rail of the fence through which I was doing this keyhole surgery was exactly and precisely where the jack handle wanted to be  A bit of rigging timber baulks and bent jack handles overcame the problem 

Leg 'C' went up it's required 4" with no real problem, and when I came to leg 'D' it was already up in the air taking no weight, so the cabin chassis must be less flexible than I'd thought.

So is it now level? Well it's certainly MORE level than it was but no it's not level. I'm going to set up the tripod and laser level this afternoon it the rain holds off - I expect that the tops of the jack legs are now roughly level but the structure of the cabin is a bit crook !

[awemawson]

This morning I prepared the timbers that will have the curved corrugated sheets screwed down to. They need the rebate to accommodate  a drip strip that having been fibre glassed is no longer easy to remove.

These started off as 6" x 2" treated timbers used as shuttering for the external concrete for the tractor shed. I cut them down to 4" x 2" and cut the 1.5" x 3/4" rebate then gave them a good coat of creosote - hopefully they will be dry enough to handle in a few days when the sheets arrive.

[awemawson]

06:30 this morning brought the delivery of the specially curved roofing sheets - shame my Forklift is away for repair (forward clutch pack) as this lot were very heavy for two of us to get off the lorry.

They'll have to stay there for some time, as it's far too windy to move them at the moment, and anyway best to wait for the Fork Lift's Return.

Just as well he came early - I wanted to mow the big field today and when on the tractor there is no way I'd hear mobile phones , gate alarms or delivery people yelling !

4 1/2 hours and 20 litres of red diesel later it's had it's first cut of the year to stunt the rush growth using that big flail mower that I rebuilt last year - it worked extremely well 

https://madmodder.net/index.php/topic,11666.0.html

[Will_D]

Just as well he came early - I wanted to mow the big field today and when on the tractor there is no way I'd hear mobile phones , gate alarms or delivery people yelling !

Andrew, when I am mowing the rugby pitches with our Deutz 95 I wear a decent set of headphones plugged into my phone. The cable these days nearly all come with a microphone and switch to answer calls. You can also tell when you get a message as the radio cuts out for a while. I bought a set from SkullCandy!!

Highly recommended.

[awemawson]

Now when I was levelling the Portakabin, at one point it slipped off the jack with an impressive crashing noise, and moved about 2 or 3 inches north at the East end 

Not too serious except for two things - there was a big gap at the threshold and as an auxiliary roof spans from this Portakabin to another it's support beam had pulled away.

Been concerned for a while how to shunt it back, but today I rested the JCB Bucket against it and gave a gentle push, and lo and behold it went back where it was supposed to be

I quickly drilled holes and put some 12 mm studding between the auxilliary roof beam and the Portakabin, so at least now they are tethered together !

Now that issue was resolved I felt more confident slicing off the Jackleg tops that might have been needed for hoisting it back from whence it slipped - un-sliced they interfere with the curved corrugated galvanised sheeting I'm using. Bally difficult access to slice them, used a 9" mains angle grinder, and I now have 'grinder rash' on my right arm from the sparks 

After this I fitted the remaining beams along the gutter line that the curved sheets will screw down to.

. . . just need to fit the curved sheeting and screw it down . . . how hard can it be . . . . . .

[awemawson]

At long last I got the curved sheets fixed and the gable ends closed today.

Yesterday MetCheck was saying that today was going to be fine however late last night they changed their mind and forecast drizzle up to 8 am then rain starting about mid-day which gave a window of opportunity.

I started by brushing the standing water off the flat(ish) roof then  lifting the first couple of sheets up, and stitching them together with self drilling screws, then came the fun wiggling them into alignment. It got even more fun as more sheets were added, especially when the heavens opened and I got drenched. This of course formed puddles under the already laid sheets with no possibility of sweeping the water away.

Anyway eventually all were up there and I started screwing them down to the board that I had fitted previously at eaves level. Went fairly well - the boards are not continuous due to the steel work of the jack legs, so there are four places where there are less hold down screws than I'd like.

Then it was a case of cutting the curved gable ends, fixing them up, and replacing the Onduline roofing that had had to be removed for access.

In all not perfect but hopefully dramatically better than before 

[hermetic]

Very hard to get perfection on a job like that Andrew, especially in the rain, flat roofs are a nightmare, I put a insulated box profile sheet over the flat roof on my workshop, adding an extra 6" of fall at the same time, and for the first time for about 20 years, I have a totally dry workshop!

[awemawson]

So at long last I found a bit of time yesterday to attack the interior.

I started by removing the pair of twin fluorescent light fittings. Pressing the 'test' button on the 30 mA / 63 amp three phase RCD breaker that is integral with the distribution board for this Portakabin I was horrified to find that it didn't trip  Probably the damp has got to it. New one on order. The inside of the light fittings showed obvious signs of water ingress.

Then I pulled out the 13a socket wiring that was original to the building - I've never powered it up as I didn't have confidence in it, and just ran a pair of twin sockets off and in close proximity to the distribution board - these later sockets I've left live to work by.

So today, after we had finished shearing the sheep, first I powered down the compressor and covered it, then I started pulling down the ceiling. Originally (probably) 4mm ply, now badly de-laminated, and insulated by 37 mm expanded polystyrene sheet, fixed to rafters spaced for 4 foot sheets.

The polystyrene I have saved as most of it is in good condition and can go back. Oddly one sheet is obviously saturated with water from it's weight, I thought that this stuff was closed cell 

The rafters have a curve on them to give the original steel roof a fall to the eaves, but three are so far gone the curvature is now downwards ! These I will have to re-make to get the new ceiling approximately flat.

A good sweep out and a bonfire and things are looking slightly (but only slightly !) more viable 

[awemawson]

Well 18 months have gone by, and at long last I have installed a new ceiling in the Portakabin.

The original one had suffered very badly from a leaking roof, rotting the thin ply ceiling and also the rather thin joists and I was at a loss to think of a good way of replacing them. When built in the factory they had laid extra large (10 x 5) ply sheets from wall to wall, then laid the joists over the ply, finally adding the essentially flat galvanised sheets to be the waterproof part.

I say essentially flat, in fact there was intended to be a slight curve to shed water, but all the joists had sagged, so that their upper curved face was in fact flat, and their lower (theoretically flat) surface sagged downwards!

I hit on the idea of adding 'sister joists' along side each joist, but jacking them up so that the curve was correct before joining the sisters.Then I had to adapt the joists and wall timbers to accept standard 8 x 4 sheets as the 10 x 5's couldn't be fitted (walls in the way!)

I chose 4 mm "hardwood throughout" ply as a compromise between longevity, weight, and price. Even so installing 6 off 8 x 4 ply panels to a ceiling single handed was quite a challenge 

It got a 'cat lick' of white emulsion paint to reflect a bit of light. I had intended to over line the walls and floor in 18 mm OSB but frankly the cost isn't justified for what is after all only a storage shed.

The entire ceiling (bar the ply of course) I re-milled from shuttering left over from building the Tractor Shed, and indeed finishing this off was prompted by having to empty the Tractor Shed and re-house all the 'stuff' that had been pulled out when the roof started leaking.

Yesterday I put a handy bench down one side using timber left over from the Scraping Class that we held here a few years back, and today I finished the electrics - a 'job done'

[Pete.]

Be alright when you get the carpets in

[awemawson]

Pete, that bench top is the somewhat cut down 8x4 of 18 mm ply that you brought to potentially make bench tops for the scraping class! I think that we eventually used shuttering ply?

The floor has a rather sad dip in it at one end, where I had been storing several tons of Blasting Grit. When I costed the 18 mm OSB3 to overlay it it came out at about £180 - just not worth it !

[RotarySMP]

I read the thread title and expected this...