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Small Buildings Installation

One of the most important things to get right for your new garden building is the foundation.

 

The main points to make sure are correct with all bases, no matter the size of building going onto it are;

 

1.It must be straight, level and square and not be susceptible to subsidence at a later date. The entire area of the building must be supported across its floor because unless specified the floor beams are not structural and therefore will bridge an unsupported

 

2.Ideally to at least the buildings footprint and where possible exactly to it, this will mean that any rain fall will drain away in to the grass / gravel surrounding the base rather than hitting a solid base and splashing up against the side of the building. The other advantage of a shed base to the exact footprint is that no water will be allowed to sit in any dips below the building which may cause the floor to rot over time. There are three main types of bases that can be used; these are listed below with some example products to give you an idea of the size of the building that they can accommodate;

 

Timber Bearers Base: this is an extremely easy solution and costs little. This method is only really suitable for smaller sheds such as one of our 6’x4’ sheds; it could also be used well on some of the smaller summerhouses.e. As a rough idea if the shed is over 10’x8’ it will need a more substantial base.

 

 

Paving Slabs Base: A simple and popular method that is useful if you may move the building in the future, the base can be removed with minimal disruption. If the groundwork is done properly this can support some very large buildings.

 

 

Concrete Base: This is always the best method especially for log cabins and the larger summerhouses. This method is always recommended if you are having a timber garage, a larger log cabin where weight is a consideration.

 

Depending on what building you are having or its eventual use it is also a good idea to incorporate a damp proof membrane into the base, this is usually applied in the sub base.

 

Timber Bearers Base: as mentioned this is the simplest and cheapest method but is only really suitable for the smaller sheds and summerhouses, certainly this shouldn’t really be used for anything much over a 10’x 8’ shed. The method is simple, firstly remove any overhanging branches, hedges, bushes etc that will effect your new shed. The area must be firm, level and square and where possible to the foot print of the building. Mark out your area suing pegs and string and then clear the vegetation, dig down to the required depth (usually about 3”-6” depending on the bearers being used) and level the area using a spirit level, make sure it is well compacted if you have disturbed a lot of soil. Once the area is level you may want to consider laying a weed suppression blanket. Lay your bearers as required onto the level ground checking them with a spirit level across both planes; you can also consider the use of bricks or slabs to lay the bearers on if there is a risk of movement over time. The best bearers to use will be pressure treated of 3”x2” dimensions, you can of course use any size you fancy, numerous people find old sleepers to be good but these are quite hard to level.

 

 

Paving Slabs Base: Paving slab bases work very well for most buildings but it can be tricky to get right. There’s a couple of ways to do it, either the entire footprint is covered in slabs, this would be the case with a log cabin. The second way is to space them out at right angles to the floor joists, and spaced evenly, normally about very 2 foot, this means less slabs are used. A special consideration for this is to make sure there is a row centrally when a two piece floor section is used, if you are unsure whether your new shed is this way configured please ask us, we’re always pleased to help.

 

The method starts as the bearers base, mark out the area and clear the top layer of vegetation. Make sure the area marked is totally square and as level as possible. A good way to check for square ness is to measure across the diagonal, each measurement should be identical. As with most things there are alternatives, you can either have a good base or a very substantial base, again this depends on the building going on it. The alternatives are a dry sand / cement or a hardcore and wet cement. Obviously the hardcore and cement base gives a very substantial base and gives a finished product as concrete bases; it depends greatly on your preferences. For this article we’ll stick with the dry mix.

 

Compact the ground as best as you can and make sure it is as level as possible, lay a layer of dry sand / cement normally a couple of inches is fine. Compact this layer and make sure this is as level as possible, back to front and side to side. Start in a corner and lay your first slab – this must be level in all planes, failure to get this correct will throw the whole base off. If a corner is too high, remove a little sand / cement, if too low add a little and use a rubber mallet or a piece of wood to bed it in. Lay the other slabs with as much care and using the same system taking leveling measurement from the first slab. It is best to do these at a row a time. The slabs must be perfectly level across the area to ensure the floor of your shed is supported throughout it’s length.

 

 

Concrete Base: This is by far the best method and will give superb support, this really is the only method for the larger shed and summerhouses especially if they are odd shapes such as corner summerhouses octagonal summerhouses. This is essential on the larger cabins such as our range of residential log cabins. The only real downside with concrete is if it goes wrong it is extremely hard to remove.

 

As a rough guide we tend to recommend bases of a depth of 3” for normal sheds or summerhouses. For log cabins or wooden garages a depth of 4” on a layer of compacted, finely broken hardcore is preferable. Ideally half the base should be above ground.

 

Start by clearing and marking the area as above. Peg the area using piece of wood set to the outside dimension, set them at each corner and then at about 2’ apart on the sides. Attached to these is “shuttering” ideally 2” thick and set to the depth of the finished base. A couple of pointer here; make sure the corners are totally square and that it is totally level across the top of the shuttering both side to side and front to back, also make sure the pegs you are using do not protrude above the shuttering – it will make it extremely hard to level.

 

Depending on the size of base you could go for the easy option or the slightly more labour intensive; if it is a large base you would be best to order in a cement lorry with the correct load, they can pour it in while you level it. For smaller bases it may be more economical to mix it your self.

 

If you’re going to mix it yourself it’s always best to be as close as possible to the base so you can shovel it in or alternatively use a wheel barrow for distances. Make sure you use a consistent measuring container for the amounts needed, a 3 gallon bucket is ideal. If the base is quite large it may be an idea to hire a cement mixer. An ideal proportion for the mix is 1 bucket of cement and 5 buckets of “all in 20mm”. This is a ballast made from gravel (20mm means the average size of the gravel) and is available at any builders merchant. “All in 20mm” is normally sold in bags of 40kg. 1.25 bags are needed on average for 1 cubic foot of concrete. As a basic rule calculate the volume required and then add a third for compaction and then add a bit as the worst thing is to be under. It is quite hard to work out the exact amount required due to the underlations of the ground so always over estimate. For an 8’x6’ shed we would recommend about 20 bags of “all in 20mm ballast” the ratio of cement to this is 1:5 so you would need 4 bags of cement.

 

Mix your concrete using the ratio above and gradually add water, don’t make it too wet as this can weaken the mixture, it needs to be wet enough to workable and fluid, keep mixing until the concrete is uniform in colour.

 

Start laying the concrete with a layer across the bottom, tamp this down and make sure it’s pushed into the corners, tap the shuttering to ensure a solid edge. Keep laying more and more layers. Starting from one end, use a beam that will cover the entire width across the top of the shuttering. Use this to level the concrete to the top of the shuttering, this is done with a sawing motion, carry on across the base area leaving the concrete flush with the shuttering. Once completed, a finish can be applied to smooth the surface using a wooden or plastic float; a special machine can also be hired to do this. Don’t try to smooth it until the concrete has gone of a little.

 

You will need to allow about 3-4 days for the shed base to set completely, remove the shuttering and finish the edges with a layer of pee shingle or grass as required.

 

If you are doing this job in the winter you may need to consider protecting the wet base from frost as this can damage fresh concrete significantly. Cover the area using plastic to giver it some protection.

 

Another small point to consider with concrete bases is if it is very large it is an idea to introduce expansion points within it, normally only needed when above about 12’x12’.

 

I hope the above is useful to you, if you are at all unsure get in contact with us and we’ll be pleased to help or you may want to consider hiring a professional to do the job.

 

 

 

 

Construction

 

This is mainly about tips for installing the Lugarde range of log cabins although much of it can be applied to many other styles of cabins that we sell

 

With Lugarde and indeed many other makes it is essential that the base the log cabin is going to be built on is flat and level, this is particularly important on the perimeter of the building – the outside edge of the base. Our installers have often found a lovely level base across the middle only to find the edges roll away, it cannot be stressed enough the values of a well laid base. Ideally the base should be to the footprint of the building; this will enable the rain to fall past the base and into the ground rather than sit on the base resulting in water being trapped underneath. We have also found it useful with log cabins to have incorporated a damp proof membrane into the structure of the base, this is especially important if it is going to be insulated and used as a studio, office, gym etc.

 

On delivery of the Lugarde you will receive 1 – 3 packages containing the parts required, it is important to check the outside of these packages for fitting instructions and a contents list. On average you should allow 2 days for the installation, and preferably this should be in dry, still conditions. It is very important that where possible you don’t allow the logs to get wet prior to installation as these can swell making it harder to put together.

 

We suggest that all the parts are unpacked and laid out carefully into there various sections. Most kits are numbered or lettered according to the wall they belong to these are normally A, B, C, and D for the four walls. The doors and windows will be already made up in there frames, these should be carefully put to one side. In the package you will also find; angled pieces – these are the bargeboards, profiled wood – these are trims for over the doors and windows, thin slats – these are also trim for use on completion. You will also have numerous pieces of T&G, these will be for the roof and floor. It is very important to consult the instructions as to the measurement for the roof and floor boards as on some log cabins they are very similar and you can easily make a mistake by using boards intended for the floor on the roof. Consult the packing list to ensure all the parts are there. Tip: when laying out the parts try to lay them away from the base to allow you space to work, try to keep them off the ground using parts from the delivery pallets, lay them in such a way that should it rain they can be easily covered up.

 

So, we have a good level base, all the parts are laid out and we’ve checked we have everything according to the inventory list; we’ll start to build the log cabin. Check the plans that have come with the building and note the position of the doors and windows and the general layout. The start of the build we consider this to be the most important part when installing the building, it is imperative that it goes down well at the start to avoid any problems when you get to the roof level and it is worthwhile spending time on the first few layers. Lay down the foundation beams, these are pressure impregnated on most makes of log cabins, our installers also recommend stapling a layer of damp proof course under these beams. The beams on the Lugarde range are held together in the corners by metal clips, other makes may suggest screwing together. Once these are laid down on the perimeter check that they are square – the easiest way to do this is measuring corner to corner. Check also that they are level and if necessary pack any discrepancies with thin pieces of wood. It cannot be stressed enough the importance of a flat and level base for the log cabin.

 

Now we can start adding the first logs, you will use 2 full size and 2 half size logs for the first layer carefully place these on the foundation beams making sure that the tongue on the log is facing up; these will then be screwed into the foundation beams. This is the only time that you should screw any logs together.

 

Tip; if the logs are tight at the joints use a mallet in conjunction with a spare packing piece to knock them in, be careful not to damage the tongue. A wooden mallet is best, we have found that rubber ones tend to leave black marks on the wood.

 

The first layer is now down so you should now work methodically round the building installing each log carefully and ensuring that you stop and check that each one is firmly tapped home. For the first 3 or 4 layers you should also check that the log cabin is still level and square. It is also a good idea to check again the plans, check how many logs are below any windows you have, it is anywhere between 3 and 5 depending on the model be careful not to go too high before looking at this.

 

Once you are at about level 4 consider putting in the door. This can be done later and indeed can be done with the entire log cabin erected; we do however recommend fitting it at about log 4 or 5 due to the weight of the door.

 

Tip; with a Lugarde cabin you have to turn the door architrave around to accommodate the 44mm wall logs. This is a common mistake made by customers and new fitters alike.

 

Install the door carefully lifting it first up and over and then sliding it down to meet the foundation beam. Fit the door furniture, lock and handles. Make sure at this point that the door is supported especially if it is windy.

 

You can now continue with the building, install the windows in the same manner as the door when the appropriate level is reached. It cannot be stressed enough the importance of making sure each log is tapped home as you build up. Reaching the top of the wall level the building should still be square and level. You may occasional find gaps above the door or windows, do not worry about these at present.

 

We are now up to the top of the wall level and ready to start on the roof. It is now necessary to build up the gable ends and any trusses; the number of trusses depends on the size of the building. This part can be quite tricky and it is necessary to take a great deal of care as if any pieces are dropped the corners can be knocked off very easily. Consult the plans and this will show you how many logs make up the apex, it will also show you the position of the roof support beams. There is a number of ways this can be built but our fitters have found it best to apply the logs and gently pin those together using pins, this stops them moving should you knock against them, you do have to remember to remove these later. This part of installation is the hardest but as long as you are careful the trusses should go in fine, once you have the first two in place you can then add the additional apex logs and any further trusses to finish the gables. Do not remove the pins just yet.

 

Next is to finally check the measurements of the roof boards against the plans, it can be very frustrating to get the floor and roof muddled up. Identify the boards and arrange a quantity of them against the inside wall. Position your ladders so one man can work in the centre and one to the outside. Fix a small block of wood onto all of the ends of the trusses, this is so you can butt up the fist roof board and to ensure it is perfectly level, try not to use your hand or eye as your interpretation can be different to the person you’re working with and result in the roof boards being applied uneven. Attach the first board to the roof truss, make sure that the flat side is uppermost and nail once through the centre of the board into each beam. Tip: On the board that attaches to the outside wall, angle the nail so it goes through the corner of the top tongue of the wall, when you are at ground level you should not then see a glint of silver from the nail and makes for a far more professional finish.

 

We recommend you now nail on 10 boards, and then swap over to the other side and nail another ten, this way you can assure that they are all lining up correctly and that the V groove is straight. When you reach an apex remember to remove the pins that we were using to tack the apex pieces. Continue alternating both sides until you reach the end of the roof. At the end you will find that you are slightly under or slightly over when you reach the end of the truss. Apply the last board and using a pencil, mark under the board, remove this, draw a line and then using a saw cut this piece and reapply. If it is very thin use some wood glue and panel pins to attach it. This will then give you a smooth finish to the roof. Remove the blocks that were attached to the first roof beams that we were using as a guide

 

So, we now have the roof boarded and are ready to felt the roof. Within the various parts that make up your log cabin you will find profiled “L” shaped pieces, these you attach to the underside of the roof boards, they should hang down below the roof line but are flush on top, screw these through to the roof boards, we usually use the black anodized screws supplied at about every 8 boards.

 

To create a professional look you now need a piece of wood of about 10mm, we usually use one of the spare pieces of trim, tack this onto the profiled piece, this will give you a guide for the bottom of the tiles so you don’t have to physically measure it each time. Cut another block of wood at about 5”, this will be your guide for the depth of the tiles.

Start at one end and the first layer of tiles is applied upside down along the bottom edge with the cut outs facing uppermost, we do this so when the log cabin is complete and you are looking up it gives a nice finish. Ensure that your first tile is butt against the end of the roof. Once you have the first layer down you can now apply the tiles as normal, the first tile of this layer will now hang over the edge of the roof by one half of a tile this is so you don’t have any seams and is a common mistake with many fitters and customers alike so please be careful. We find it sufficient to apply a felt nail to each end and one off center. If you are installing your cabin during the cold months we would also recommend that you use a small amount of silicon in each corner of the tiles to stop them lifting in high winds. This is not usually necessary in the hot months as the tiles melt into each other and form a good fixing and remain so over the years

 

Continue up the roof using the block spacer you have cut to measure the depth of the tiles when they overlap each other, always work from one end and ensure each tile is overlapping each other so there are no seams. On completion you can now remove the 10mm splines. This should now leave you with a nice overhang on the roof edge and straight lines on the tiles themselves. To finish you now need to lay tiles over the ridge. We find it very helpful to cut these individually on the ground, and then cut them again giving a slight angle each side on the top part; this will help them to fold better. These are then applied to the ridge and once again use the block spacer to create a professional finish.

 

When completed you can now add the barge boards, these usually consist of the facing ones and then separate boards that go on top of the ends of the roof. We find it best to screw these as if you ever need to re-roof the log cabin they will come off easily.