Garden Building Fire Safety and Cladding Fire Ratings

Installation Process of Fibre Cementboard Cladding

Choose your Garden Building cladding very carefully. It is tempting to select something just for its wonderful appearance, however the cladding selection greatly impacts the fire safety of the building. In this article we will provide an outline of what to look for when selecting your cladding for your Garden Building.

British Standard 476: Fire Tests on Building Materials and Structures

Construction products have one of the following 3 labels. The three labels relate to a products mandatory reaction to fire classification in the UK. This can be achieved through the National classes, using the BS 476 suite of tests resulting in one of the following 3 labels:

  • A1 / non-combustible
  • A2 / of limited-combustibility
  • B-F / combustible

BS EN 13501-1: Fire Classification of Construction Products

BS EN 13501-1 is the standard fire classification assigned to construction products that enable products to be CE Marked, as required by The Construction Products Regulation (EU) No 305/2011

To CE Mark products, they must be classed through the Euroclass system. The Euroclass system has 7 levels/ratings. This is the first measurement of BS EN 13501-1 classification:

  • A1 – Non-combustible
  • A2 – Limited combustibility
  • B – Combustable
  • C – Minor contribution to fire
  • D – Medium contribution to fire
  • E – High contribution to fire
  • F – Easily Flamable

The second measurement of BS EN 13501-1 classification is smoke emission during combustion:

  • S1 Quantity/speed of emission absent or weak
  • S2 Quantity/speed of emission of average intensity
  • S3 Quantity/speed of emission of high intensity

The third measurement of BS EN 13501-1 classification is the level of production of flaming droplets/particles during combustion:

  • D0 No dripping
  • D1 Low dripping
  • D2 High dripping

So, now we have our definitions, let’s look at how this applies in a practical application for your project. When you select any construction products, look for the 6 digit code which should be alongside the classification EN 13501. Note you may also wish to look into EN 12467 to check durability and strength classifications at the same time.

Choose Cladding with a Euroclass Fire Rating

  • As a homeowner, the safest method of cladding selection is do not use products which do not have a Euroclass fire rating, specifically for cladding. These cladding products have not been submitted for approval for a reason. It may be because they are not required for approval across multiple geographic regions which use the Euroclass system, however there is no shartage of options for products which do have a rating. We would not recommend products which do not have a clear Euroclass rating, regardless of the manufacturers reasoning for not getting their products tested.
  • Products should be clearly CE Marked, have the classification EN 13501, and have a 6 digit code which includes all 3 ratings.
  • In most cases you will need to find the Declaration of Performance or Product Data Sheet on the manufacturers website as most retailers do not display this information on their websites.

For example, we had a recent project including a Garden Building where the fire rating was classed from day 1 as important to both us and the end customer (and their children most importantly). We used Cedral Weatherboard Fibre Cement Cladding which is rated A2-s1, d0. To break that down that is:

  • A2 – Limited combustibility
  • s1 – Quantity/speed of smoke emission absent or weak
  • d0 – No dripping of flaming droplets during combustion

Building regulations and fire proof materials for Garden Buildings:

The text below is directly taken from the UK government Planning Portal. One key element to note is at the very bottom in bold. if you are building your garden building within 1 mt of your property boundary your garden building must be constructed substantially of non-combustible materials. If you don’t, you can be asked to amend it, or remove it, at your expense. Best to do it properly the first time.

From the Planning Portal:

If you want to put up small detached buildings such as a garden shed or summerhouse in your garden, building regulations will not normally apply if the floor area of the building is less than 15 square metres and contains NO sleeping accommodation.

If the floor area of the building is between 15 square metres and 30 square metres, you will not normally be required to apply for building regulations approval providing that the building contains NO sleeping accommodation and is either at least one metre from any boundary or it is constructed substantially of non-combustible materials.

This section provides you with general information to help you comply with the Building Regulations when constructing a new outbuilding within the boundaries of an existing property, such as:

  • garage or carport
  • summerhouse or shed
  • greenhouse

Building a new garage attached to an existing home would normally need building regulations approval.

Building a new attached carport (open on at least two sides) would not normally require building regulations approval if it is less than 30 square metres in floor area.

Building a detached garage of less than 30 square metres floor area would not normally need building regulations approval if:

  • the floor area of the detached garage is less than 15 square metres.
  • the floor area of the garage is between 15 square metres and 30 square metres, provided the garage is at least one metre from any boundary, or it is constructed substantially of non-combustible materials.

How to choose the correct screws for decking and outdoor projects

choose the correct screws for decking Oilcanfinish Landscapin

What the homeowner wants to see is a perfect installation, not rust lines and stains formed shortly after installation. How to choose the correct screws for decking and oiutdoor projects is crucial planning information to ensure your project doesnt suffer from damage to wood and steel, Rust dripping onto paving resulting in staining, and fixing failure potentially resulting in permanent damage to the structure which was just installed.

As a consumer, one of the main issues is a lack of information of which product to use combined with a lack of clarity on product packaging regarding levels of corrosion resistance, suitable installation use, and usable life.

Issues using incorrect fixings

Corredere (latin) Corrosion, for Fixings the oxidisation of iron causes rusting.

These are the 4 main types you will need to be aware of when planning your garden construction, whether it is a Garden Building, Decking, Pergola, Fencing, Seating or Garden Furniture, or whatever else it is you are building.

  1. Armosperic Corrosion, the main causes are when the iron in metal is exposed to too much moisture (water) or oxygen Metal corrodes when it reacts with another substance such as oxygen, hydrogen, an electrical current or even dirt and bacteria.
  2. Chemical (Dry) Corrosion occurs on a location where a given metal is under stress or isolated from air circulation. It occurs whenever a gas or liquid chemically attacks an exposed surface, often a metal, and is accelerated by warm temperatures and by acids and salts. This includes Galvanic (Bimettalic) Corrosion, when 2 dissimilar metals are immersed in conductive solution together. Avoid by separating materials, use the same materials, coating both materials, installing a sacrificial anode.
  3. Contact corrosion, metals of different types are in contact with eachother (A2 and Galvanised for example)
  4. Extranneous Rust comes when objects that rust coming into contact with stainless steel. This includes using tools which have previously been used with Carbon Steel which are then used on stainless steel leaving some carbon behind (such as Impact Driver Bits), sparks when using an angle grinder, or water containing rust dripping onto stainless steel.

So, what products are out there? Which products should you buy?

Stainless Steel A2 and A4

  • A2 304 Stainless Steel – interior and exterior uses, kitchens and bathrooms, humid areas, high chrome content
  • A4 316 Stainless Steel, marine grade, – interior and exterior use near salt water in coastal areas, high chrome content
  • Recommendation: There are very situations where A4 is required, unless you live near the sea (or near a chemical factory)

Hot Dipped Galvanised vs Electroplated Galvanised

  • Galvanised via Hot Dipped treatment (zinc with galvanised coating) exterior use
  • Galvanised via electeoplating (bright, shiny, zinc yellow passivated) bad for Redwoods, Spruce, Treated Timber leaving black marks around screw head leading to rust. These are recommended for interior use, not in bathrooms or kitchens.
  • Recommendation: Do not use Electroplated screws for exterior installations. They will rust very quickly.

Ruspert/Silverised vs Painted/Plastic Coated

  • Ruspert (trademarked brand), Silverised exterior use
  • Painted or Plastic Coated Carbon Steel (!) Carbon steel does not have enough chromium to form a chromium oxide layer. This allows oxygen to bond with the iron in carbon, resulting in iron oxide, or rust. 
    • The impact driver bit you use to install them will scratch off the exterior paint or plastic coating and the carbon will be exposed seconds after install them… Just don’t use them. 
    • You will find boxes of 2500 Coated Carbon Steel Decking Screws for £20.00, keep shopping. Note this is a popular screw choice due to its price, it results in lower decking installation quotes. The rust formed on these screws will increase the breakdown of the wood at the cut ends, we see this weekly. Generally the screws are Green or Brown. When removed the entire thread is covered in rust which destroyed the wood around it, specifically Redwood Decking.
  • Recommendation: For tasks such as wood to wood structural fixings look for treatments such as Ruspert, Silverised, C2 (Timco), or Wirox (Spax).

Applications & Head Types: Choosing the correct screws for decking and outdoor projects

Here are the screws we use for Cladding & Fencing & Decking projects:

  • Nails
    • Cladding & Slat Fencing – Lost head nails
    • Featheredge Fencing – Clipped head or Round head nails
      • The issue with lost head is also its advantage. Lost heads are tapped down so they are almost invisible while clipped or round head have a small round circle which is visible. The round head pulls the cladding towards the support batten, the lost head does not. Style-wise the increased demand for hidden fixings does slightly reduce the force holding the cladding in place
    • Nail Shank – ring shank for added holding ability, less nail movement
    • Nail Material – stainless steel or hot dipped galvanised, we use stainless steel wherever possible
  • Screws
    • Cladding – Spax Stainless Steel Fassade installed with a Wera Stainless Steel driver bit
    • Fencing – Jacksons Fencing Screws for Timber Fencing
    • Decking projects – Trex Decking and Millboard decking have their own screws which we use. We also use these screws for Hardwood Decking Projects

Here are the screws we use for Structural Projects such as Pergolas, Carports, Decking Projects:

This is where load bearing is the most important aspect for safety and durability reasons. We use Spax High Force Washer Head or TIMco A4 Stainless Index Screws depending on how exposed the screw head will be to water (TIMco A4 for high, direct exposure, Spax for indirect exposure). We find the Spax screws visibly pull the materials together.

Installation Notes

  • SS is Non-hardened so easier to strip the heads, go slow, do it once, then leave it. Especially with Pan Head screws.  Removing and reinstalling the screws is a mistake.
  • Don’t use impact drivers unless on very low vibration settings with brand new, clean bits which are made of the same materials being installed. High vibration tools make small cuts in the  protective coating on the screw or bolt right at the head which is especially damaging on applications which are horizontal (decking) where the screw head will “catch and hold” water.
  • Extranneous Rust – We use Stainless Steel driver bits to prevent extranneous rust getting onto our Screws. This is when a small amount of rust on the bit gets onto the screw when installed. It also comes from wrenches, pliers, sockets, and spanners. Use stainless tools for stainless fixings.

Other Treatments to be aware of:

Re-galvanising Spray 

If you are cutting galvanised brackets, door latches, etc… First remember this gives off poisonous fumes so wear the correct mask, do it outdoors, and use a hand saw vs an angle grinder or cut off saw. Second, file down the burrs and then respray the cut end with re-galvanising spray. You can get this is a small spray can from most tool and material suppliers, I got mine from Screwfix. Watch your overspray and let it dry before installing.

Lithium Grease

Spraying exterior metal with a Lithium Grease, such as WD-40 White Lithium Grease will not only keep moving parts lubricated but also protect it against rust. Handy for garden tools as well. Again, a small spray can with nozzle from Screwfix will last you a long time.


This is something you cant do at home. Powdercoating is a method of painting which results in a consistent, strong, protective finish to metal. You often find this used as a finish for Car Parts  or in our case, Exterior Brackets for Fencing, Pergolas, Sleeper Beds and it provides an additional layer of protection to the Galvanised product underneath. You can find specialist companies which will Powder Coat your steel products. Powdercoating is not an alternative to galvanising, but an enhancement to it.


There are several paints which are specifically designed for steel. Zinnser, Andura, and Hammerite being some examples. Automotive and Marine Grade paints are ideal. These do not last as long as they used to, probably with the removal of hardful ingredients we used to all ignore. Ensure what you are painting is as clean as it can be, free of any flakes or peeling. Use a sander/polisher to fully clean out any pitted areas and paint your object in a clean dry area free from dust. Remember the work area has to remain clean, dry, and free of dust until the paint has set. Car Bodyshops used to spray water on the floor prior to painting to keep dust down, not sure if they still do, but thats what I do.

Resources and Links

British Stainless Steel Association https://bssa.org.uk/

Exterior Screws, Bolts, and Nails

Spax https://www.spax.com/uk/

Timco https://timco.co.uk/

Jacksons Fencing https://www.jacksons-fencing.co.uk/

Stainless Steel Tools & Exterior Brackets

Wera https://www-de.wera.de/en/

S3i https://www.s3i.co.uk/

Simpson Strong Tie https://www.strongtie.co.uk/

Jacksons Fencing Replacement Project in Surbiton

Jacksons Fencing Approved Installer

This project was a straight forward fencing replacement project in Surbiton. The old fence was removed and we installed a new property boundary fence along one side of the large garden. The new fence selected was Jacksons Fencing Chilham Fence Panels, alomng with Jacksons Fencing posts, gravel boards, and capping rails. The clients decided to go for 1.8 metres in height, so 1.65 metre Chilham fence Panels and 14cm Gravel Boards.

The biggest advantage of Jacksons Fencing Chilham Fence Panels is they look the exact same on both sides, so neighbors will like them as well as there is no bad side to them. They are based on a classic board and batten design however with Jacksons planed and chamfered timber they have a modern twist to the traditional fencing design.

Jacksons Fencing come with a 25 year guarantee making it a safe investment compared to other options. The cost of replacing fence panels and/or posts two or three times over 25 years includes the cost of materials, but also the cost of multiple waste removals, the labour to install the fencing multiple times, and you also have the advantage of looking at a beautiful handmade fence. Over a 15-25 year length of time, no other fencing product will have the same return on investment.

This fencing project had 1 elevation change, from the decking down to the lower grass area which makes up the bulk of the garden. The clients preference was no visible partial fence panels so we stepped the full panel out from the patio, which also provides more privacy on the upper patio area. The fence then drops down after it extended out past the raised patio by 1 metres. This required reinforcing the triple gravel boards to ensure they stay in position and do not twist and separate over time.

Oilcanfinish Landscaping are Jacksons Fencing Approved Installers. Visit Jacksons Fencing website to explore the full range: https://www.jacksons-fencing.co.uk/

Kingston Upon Thames Jacksons Fencing Approved Installer

Oilcanfinish Landscaping is a Jacksons Fencing Approved Installer

Oilcanfinish Landscaping is a Jacksons Fencing Approved Installer. Jacksons Fencing produce premium quality fencing, decking, pergolas, sleepers, and landscaping materials for residential and commercial installations. They are based in the UK and were founded in 1947.

Jacksons Fencing timber comes with a 25 year guarantee against all wood-boring pests and all forms of wet and dry rot.

Jacksons Fencing includes a wide variety of styles to suit traditionalists and customers who prefer more modern, stylish designs. We recommend all customers take a good look through the Jacksons Fencing website here. If you prefer we can send you brochures and would be happy to discuss the different varieties of fencing available.