Log Cabin Base Preparation
One of the most crucial parts when purchasing a Log Cabin. With a successful base installed the longevity of your cabin will be at its utmost.
Building a log cabin greatly differs to building a shed which most may not realise. When building a shed the floor usually goes down first, then the walls and the roof. However, due to the weight distribution a cabin is builtwith the walls first, followed by the roof and then the floor is left until the end. The flooring is nailed in place to each floor bearer but aren't load bearing, the cabin walls hold the entire load of the cabin. Therefore, when laying the base bear these factors in mind as the weight is concentrated around the perimeter of the cabin.
When constructing a base particular care must be taken to ensure the edges are capable of supporting 2-3 tonne in weight; edges must be strong and sturdy, not crumbling nor chipped.
Which Materials to Use for a Base?
The base can either be constructed by forming a concrete slab or laying concrete slabs.
If you decide to form a concrete slab, either with "ready-mix" concrete or by mixing the concrete yourself, the poured concrete must sit on a good layer of compacted hard-core. Prior to pouring the concrete there must be a minimum depth of 100mm for the concrete to fill.
If a concrete base if constructed, the wet concrete should be compacted tightly against the shuttering to ensure no gaps or large pockets of hardcore. Also, make sure the cement has seeped inbetween the hardocre to provide a strong bond.
By laying a damp proof membrane under the concrete will prevent moisture from seeping through the ground soaking up potentially into the bearers of the cabin. A layer of sand will need to cover the hard-core to prevent any puncturing of the damp proof membrane when the concrete is poured. Furthermore, another highly favoured recommendation is that a concrete base is formed so that the its size extends to the outer face of the walls.
As an alternative concrete slabs could be used. Prior to laying slabs there must be preparation. Start by including a good layer of compacted hard-core, then a dressing of sharp sand and then the slabs must be cemented in place using either a wet or dry mix.
Whichever base is used, it is critical the base does not run out of level by more than 10mm end to end, is square and solid, with no possibility of slump or movement. It is therefore, also important the ground is also properly prepared before the base installation by levelling and the removal of all loose soil and replacing with a compacted layer of hard-core. Timber frame bases are not always recommended but are ideal is the ground falls away in one direction, as they can easily be raised using timber uprights concreted into the ground.
How Important is a Level Base?
Forest manufacture their log cabins with the use of cutting edge technology with high precision engineering machinery to mill the timber. All logs are designed to interlock perfectly to prevent water and wind ingress. This is due to the way the logs are stacked on top of each other and how they interlock therefore, leaving little, if any room, for tolerance. Thus allowing the cabin to perfectly manage any vertical force. but will not manage lateral forces if the base isn't level.
As an example, when a builder constructs a patio they will include a slope to help water run-off. If then a log cabin is built on the patio it will be exposed to the lateral forces of gravity pushing it in the direction of the slope. Therefore, making it difficult to construct the cabin, causing the logs to buckle and warp and the roof to twist.
For these reasons it is imperative that all log cabin bases are completely level from edge to edge and corner to corner. Sloping any more than 10mm between these points will incur the following problems:
- Logs will not interlock, they will twist and warp.
- Gaps will be noticeable between the top logs and the roof.
- Doors and windows will not sit square, preventing them from opening and closing efficiently.
- The floor and roof boards will not sit square to the cabin walls; highly noticeable to the naked eye.
- When the cabin expands and contracts throughout the seasons, the logs will split and crack, warping and twisting will be more evident and gaps will appear in between the logs and joints causing water and wind ingress.
- As each season passes these factors will worsen.
Delivery of your New Log Cabin
Forest provide a kerbside pallet drop delivery. They use a crane off-load heavy goods vehicle, meaning that unfortunately they cannot unpack your log cabin and take the goods around the back of the property. They usually plan to deliver to the front garden or drive, it is important that there is sufficient space and access for your order to be delivered.
They suggest that if a Fire Engine can access the delivery point then their vehicle will also be able to. Health and Safety and insurance liabilities prevent the delivery drivers from entering your property for access. For example, if you live in a terraced house or request delivery to an allotment, they will still only be able to delivery to a point of the property adjacent to the roadside.
Forest will always ensure that your order is delivered to the nearest point to your property that is adjacent to the roadside, subject to it being legal parking and clear of obstructions. Please be mindful of trees, pedestrian crossing, non-stopping red routes, etc when advising a location to deliver to.
The cabin will be delivered on 3 pallets. The largest one contains all the timber components, the second contains the windows and doors and the third has the rolls of felt or felt shingles strapped to it (dependant upon what your have ordered). The largest package will usually measure 1.5m x 1.5m x the length of your cabin. It is highly important that you have the correct space to store your cabin once delivered, until it can be installed.
Upon Receipt of the Goods
We always suggest you inspect both the packaging and goods before signing the delivery.
Please allow enough time for the product to be delivered and inspected before booking a tradesman. Ourselves and Forest cannot be held responsible for any out of pocket expenses incurred due to products being unavailable, damaged or a delay in delivery.
Please note that the delivery drives are unable to remove cabin packaging. Transit packaging will be left with the goods to avoid damage or deterioration until you are in a position to construct your purchase. This also applies if you have booked Forest's installation service.
Log Cabin Installation
Before you start do not attempt the assembly of your cabin until you have checked the component list which is at the back of the drawing sheets. This is to ensure all parts are present to aid the installation of your new cabin. If you have missing or damaged components please notify us or Forest within 3 days of receiving the cabin.
The build fo the cabin is fairly straightforward for anyone with a high standard of DIY or who has building experience. Generally, it does not require any special skills, but does require a logical approach and possibly require some general carpentry.
Special attention should be paid to the possibility of surrounding raised ground draining onto the slab or under your cabin. Building the base correctly is highly important- corner cutting here will result in a difficult build as well as impacting the longevity of the cabin.
Aftercare Top Tips
You may think everything is done after the instillation however, if you want your cabin to provide years of luxury relaxation/entertainment then there are some steps you should follow after the construction. Numerous actions need to be sought out to ensure the cabin is rot proof, waterproof and watertight.
Protecting Against Rot
Log Cabins come untreated (except the bearers as they have direct contact with the ground) therefore the correct application of treatment is required; as soon as possible after installation. Ideally within 7 days of the build.
Forest recommend the use of a solvent based preservative such as Barrettine Preserver as it is slower drying than water based alternatives.
To start the treatment process apply two coats of preservative to the exterior and interior of the cabin. These preservatives contains substances that prevent the build up of fungi, mildew and wood boring insects. Some of the fungi can potentially be very harmful to the cabin which causes rot.
Weatherproofing your Log Cabin
As timber is a natural product it will always try to reach a moisture equilibrium with its surrounding environment which causes the cells of the wood to continually expand and contract. Furthermore, any untreated timber exposed in rain can expand rapidly. The largest percentage of timber related problems are linked to movement, including twisting, splitting, bowing, warping, cupping along with other potential problems.
UV rays from the sun can also bring issues to your timber, which some may not think of. These rays break down lining in the surface cells of the timber causing it to go a grey colour, even though this doesn't harm the timber in anyway, it does look unsightly.
High quality exterior timber finish must be applied to your cabin which offers protection from the extremes of our climate within the UK.
The two most common types of high quality exterior wood finish are penetrating finish and film finish.
Both are quite self explanatory, penetrating finish provides protection that goes deep into the wood and film is a protective layer on top of the wood.
Penetrating finishes are predominantly oil or wax based and they work through soaking into the surface layers of the timber to provide a tough, durable, weather resistant finish. This type of finish is thin in viscosity to ensure it can penetrate the microscopic pores of timber. The more coats that are applied the further the finish penetrates the timber and the better protection against UV rays, because of the build up of pigment.
Penetrating finishes are extremely easy to apply and maintain. Once surfaces become to look worn and tired, simply re-apply a fresh coat, no need to spend hours sanding and stripping back the old finish. Which makes life simple for patch repairs to be fixed and blended in with the surrounding areas.
Film finishes are polymer resin based and are usually Alkyds or Acrylic, which bond together during the drying process to form the film. These types of finishes are constructed in such a way that the top coat will start to deteriorate, lose its colour and sheen, this is when maintenance is required. The more layers coated on the timber, increases the thickness of the film layer.
One of the most fundamental aspects before applying a film finish is preparation. A primer coat is essential to ensure the film finish has something to adhere to, without this the finishes can crack during movement of the timber. Thus leaving the timber exposed and vulnerable to water seeping in and resulting in the film peeling away from the timber. If cracking or peeling occurs the entire finish has to be removed using a heat gun and scraper.
Recently a third finish type has entered the market and is becoming highly popular. This is a penetrating and film finish hybrid. Offering the advantages of both which provides superior timber protection. Another bonus, it doesn't crack or peel and is easy to apply and maintain.
In order to validate your guarantee the following finishes must be used on the exterior and interior of your cabin:
- Sikkens Cetol HLS Plus
- Restol Wood Oil
- Timmersol ETS Double Protectant
- Osmo Country Colour
- Osmo Natural Oil Woodstain
The inside of your cabin is classed as exterior, never be tempted to use an interior grade finish inside your cabin as, interior finishes will simply not stand up to the constant movement of the cabin timbers.
Ensure the doors and windows have been sealed using a clear silicone sealant, on the outer and inner frames and where the frame meets the glass.
If you have followed our guide you will now be able to enjoy your new log cabin for many years to come.