A (temporary?) base for a sectional garage

[oldkettle]

I have recently picked up a sectional garage on freecycle. We have some kind of a patio in the middle of the garden and I am considering putting this garage there to serve as a storage/workshop as the existing garage will have to be demolished soon. The area is reasonably flat but is not level so I am looking for the easiest way to make it a suitable base. I am not sure we will want this building there permanently - it is in a nice sunny location and I'd rather move it eventually, so don't want to create future problems.

It's not quite clear to me whether the existing base is just paving on a thin subbase or there is some concrete there - see the picture, the grass it definitely growing through the sealing. It has been stable over 6+ years we've been here. The two options I was considering were screed over the top (but how much of it?) or lifting the stones and putting in a thin (75mm? 100mm?) slab, the latter sounds more difficult to get rid of in the future though. I guess alternatively we could just use a single layer of paving bricks or concrete for the perimeter only to level things and leave the middle as is? 

Ah, and of course it's on a slope to make life easier  

 

Any advice is greatly appreciated.

[Russell griffiths]

Have you been to collect this garage .?

do you have the ability to move it ?

there is a reason that they are free. ,!!

[oldkettle]

7 minutes ago, Russell griffiths said:

Have you been to collect this garage .?

do you have the ability to move it ?

there is a reason that they are free. ,!!

 

 I have and this garage has been in my garage for a month ? The panels are movable - some I can shift alone, some need a mate.

[Russell griffiths]

Then chuck it up on that paving, c’mon stop dawdling. 

Picture tomorrow night of it finished. ?? 

[oldkettle]

10 minutes ago, Russell griffiths said:

Then chuck it up on that paving, c’mon stop dawdling. 

Picture tomorrow night of it finished. ?? 

 

? But one corner is about 70mm higher than the other. The panels just won't stand straight either.

[Russell griffiths]

1 hour ago, oldkettle said:

 

? But one corner is about 70mm higher than the other. The panels just won't stand straight either.

I thought you only want it for the length of your build ??

pack it up on a few bits of timber then chuck a stiff concrete mix under the panels to fill the gap. 

[oldkettle]

6 hours ago, Russell griffiths said:

I thought you only want it for the length of your build ??

pack it up on a few bits of timber then chuck a stiff concrete mix under the panels to fill the gap. 

 

Measured properly with the laser level tonight and it's worse, 130mm difference. I guess packing with timber is out of the question. 

[Bitpipe]

A standard block is 100mm so maybe use a course of those and then some timber on top to pack out?

[oldkettle]

2 hours ago, Bitpipe said:

A standard block is 100mm so maybe use a course of those and then some timber on top to pack out?

Thank you. I feel the main problem is that AFAIK it is not possible to make a stable layer of concrete if it is too thin (and I never actually used any before ? ) . A friend came around today and it seems the best idea so far is  starting with a single row of paving bricks at the highest point and then bringing the other corners up to the same level with more bricks and mix, 3 rows at the lowest point. 

Edited July 11, 2021 by oldkettle

[oldkettle]

A change of plans: after another discussion with a friend I've decided to position the garage on the opposite side where it will not be occupying the sunniest part of the garden.

As shown in the picture, it's next to the conifers which I will cut heavily for now (most likely all the way to the trunk) thus giving me space to move the base closer. Then I will put aggregates down and cover with paving stones.

There are a couple of questions - I hope somebody can advise.

 

1) I have textile  membrane (the same I bought to put under the delivered aggregates) and plan to use it but taking into account the proximity of the trees is it worth putting down heavy duty landscape fabric first?

2) the difference in levels is significant - about 400mm over 5.5m of length. I don't want to build retaining walls around the base if possible. Can I lower the far side somewhat (200mm?), dig a little trench above it and fill it with gravel? Our ground is relatively free draining due to sand and likely the slope, I don't think there is a significant risk of flooding there. At least if I need to raise the bottom part 200mm above ground I won't need to worry much about the whole base moving as opposed to the full 400mm. A friend also suggested adding a mix (cement + sand) around the perimeter and letting the whole thing set naturally.

 

 

Edited August 9, 2021 by oldkettle
fixed the pictures

[oldkettle]

Bump.

Any advice?

[markc]

Any geo membrane will be fine,  and nothing wrong with digging in a few hundred mill.

sectional garages do not put much load down and certainly to point loads so the base doesn’t have to be anything serious. We have free stood them on bare soil as temporary stores and they didn’t sink much at all.

[oldkettle]

2 hours ago, markc said:

Any geo membrane will be fine,  and nothing wrong with digging in a few hundred mill.

sectional garages do not put much load down and certainly to point loads so the base doesn’t have to be anything serious. We have free stood them on bare soil as temporary stores and they didn’t sink much at all.

 

Thank you. Yes, I agree the sections are not heavy, it's only since I have to level the base anyway I am trying to do it reasonably well.

 

No need for an extra root protection (i.e. vs tree roots) using a landscape one?

Anything special I need to do to make sure I don't get water in from underneath apart from sealing the gaps between the pavers/around the sections?

[oldkettle]

A bit of a progress with laying the base. Managed to get 6F2 down and wacked reasonably well although not sure how much soil was in the aggregate. It is relatively level but requires bedding I guess. Should I use sand or dry or wet mortar mix now for the pavers? A bit concerned about just sand due to the slope as you can see in the picture - the front is slightly above the ground already. 

[oldkettle]

22 hours ago, oldkettle said:

A bit of a progress with laying the base. Managed to get 6F2 down and wacked reasonably well although not sure how much soil was in the aggregate. It is relatively level but requires bedding I guess. Should I use sand or dry or wet mortar mix now for the pavers? A bit concerned about just sand due to the slope as you can see in the picture - the front is slightly above the ground already. 

 

Bump. I appreciate this is much less exciting than Brexit.

I am quite close (am I?) yet can't get this finished properly without some guidance. 

[George]

Here you go: https://www.pavingexpert.com/blocks

 

Best resource available on laying pavers. Used it a lot in specifying civil engineering works! 

[oldkettle]

1 hour ago, George said:

Here you go: https://www.pavingexpert.com/blocks

 

Best resource available on laying pavers. Used it a lot in specifying civil engineering works! 

Thanks George 

 

I know the site and checked it several times. The issue is there is a slightly different advice in different places. They show how to use sand for paving stones but do mention the mix somewhere else. 

I need to understand whether I have to arrange a rigid border around the whole thing or not to keep the base stable and what is the simplest way forward in my specific case: sand, 2-6mm grit or some mortar mix. If it was just a garden path or a patio I wouldn't bother too much. 

Edited September 27, 2021 by oldkettle

[George]

There is a lot of seemingly conflicting guidance but unfortunately that's usually because 'it depends' 

 

In your case, you should be doing flexible block paving (assuming you are using those clay pavers pictured above)

 

https://www.pavingexpert.com/blocks2

 

You need either a kerb / edging block / something solid to edge the perimeter of the block paving. These need to be haunched with a sand/cement mix, or a concrete mix. The inner blocks can be laid onto non-cementitious bedding sand. 

 

For bedding it needs to be sharp sand, ideally washed (so salt content is lower) .

 

Jointing sand to fill the gaps between pavers. 

 

 

[oldkettle]

3 hours ago, George said:

There is a lot of seemingly conflicting guidance but unfortunately that's usually because 'it depends' 

 

In your case, you should be doing flexible block paving (assuming you are using those clay pavers pictured above)

 

https://www.pavingexpert.com/blocks2

 

You need either a kerb / edging block / something solid to edge the perimeter of the block paving. These need to be haunched with a sand/cement mix, or a concrete mix. The inner blocks can be laid onto non-cementitious bedding sand. 

 

For bedding it needs to be sharp sand, ideally washed (so salt content is lower) .

 

Jointing sand to fill the gaps between pavers. 

 

 

 

I am using large 600mm concrete paving slabs. I am planning to put the garage sections in the middle of the perimeter slabs and then was planning to put smaller 450mm ones outside to have a nice wide path to walk around. So I guess I have to set this edge in a mix as you describe and then just use sand. Great, much cheaper than grit it seems. The only issue is edging will have to sit between the perimeter and path slabs which is a bit of a pain. 

Thank you, will give this a go then. 

[George]

Oh if you're using slabs then you're better off setting into cement:sharp sand bedding throughout.

 

https://www.pavingexpert.com/pccflag1

[oldkettle]

Resurrecting this since the garage is now in place (well, has been for over a year). Apart from the roof sheets, everything was moved singlehandedly by yours truly (and hence the walls are not quite as straight as they should have been). In the end I've not set the slabs into any mix. One of the reasons was I didn't have enough of them to fill in the whole space - only the perimeter. Might have been a mistake but with all the weight above I doubt they are going anywhere.

 

It's fine as a storage but the dirt and organic material will inevitably get everywhere and I can't use it as a workshop as it's impossible to sweep. I have enough slabs now to fill in the middle. I also have paving bricks as an option.

 

What would be the easiest thing to do:

1) bricks sealed by dry or wet mix (?)

2) slabs sealed the same way - I don't think I need to bed them at all as there is nowhere for them to go to be honest

3) just concrete mix over the compacted base; the concern here is I only have about 50-60mm of depth to play with, although nothing too heavy will ever be put on this slab

 

I feel 2 may be the easiest as it doesn't require mixing a lot of concrete (which I've never done before and quite curious to try actually)? Watched a few videos on sealing patios, not sure whether this would be much different.

I do have a similar problem outside where there is a 100-300mm gap that has to be covered as well. Too small for slabs. Put smaller slabs over the top temporarily to keep the weeds off but want a permanent solution.

 

A few photos for illustration.

 

[George]

Think I'd just concrete the inside. Otherwise dealing with the gaps/joints will be a never-ending frustration.

 

mixing concrete = easy

laying concrete = easy

leveling concrete = tricky

 

Plenty of YouTube help or an experienced friend is well worth the beer cost.

[oldkettle]

7 hours ago, George said:

Think I'd just concrete the inside. Otherwise dealing with the gaps/joints will be a never-ending frustration.

 

mixing concrete = easy

laying concrete = easy

leveling concrete = tricky

 

Plenty of YouTube help or an experienced friend is well worth the beer cost.

 

All true, but is 50-60mm depth enough? Every time this question was asked the reply was "no, need at least 100mm". I can remove some of the blinding layer of 2-6mm shingles, but not another 50mm. And adding 20mm over the slabs is probably even worse. 

 

I will still have to deal with the joints between the perimeter slabs of course. 

[HughF]

50-60 is fine, chuck some mesh in there. It's a shed at the end of the day...

[oldkettle]

10 hours ago, HughF said:

50-60 is fine, chuck some mesh in there. It's a shed at the end of the day...

 

Right. I just moved the content of a bulk bag of sharp sand 125 steps up to the garden after a curb-side delivery and thought I was done. Now I need to order ballast and repeat the exercise 🙂