Stainless steel screws for decks – when and why
A deck with stainless steel screws – when and why?
Stainless steel screws have high corrosion resistance, so they can be used in almost any environment. Stainless steel screws are also more ductile, so they cope better with the stresses that arise in timber structures.
Stainless steel grades
Stainless steel screws are made in two grades – A2 and A4. Screws made of stainless steel A4 (acid-proof) have the highest corrosion protection (corrosion resistance class C5) and the most ductile steel; A2 screws have slightly lower corrosion protection (C4) and slightly less ductile steel.
Below we explain:
- When to use A4 screws
- When to use A2 screws
- How deck cleaning and de-icing salt affect the screws.
When should you use screws made of acid-proof stainless steel A4?
Screws made of stainless steel A4 are always a good choice when building a timber deck. You can use them regardless of the climate, environment, type of wood and size of the deck. They are the best guarantee that the deck will last for many years.
Here are a few examples where screws made of acid-proof stainless steel A4 are a must.
Decks on the seashore (salt water)
Boards swell in a humid environment, so the deck structure moves more and the joints have to withstand the movements of the wood. The salt in seawater increases the risk of rust, so the highest corrosion resistance is needed.
Decks next to swimming pools
As on the seashore, decks next to swimming pools need screws with the highest corrosion resistance because of the aggressive environment.
Decks made of exotic wood
Boards made of exotic wood species deform much more than pressure-treated timber, so you need screws that can withstand the movements of the structure without any risk of damaging the joint.
A high-quality decking screw made of acid-proof stainless steel A4
Choose from premium ESSDECK Max screws with exceptional clamping force and a neat look once driven, HDS screws for hidden fixing, standard Classic screws or collated screws.
ESSVE Decking screw ESSDECK MAX 4.8 x 55 mm A4, pack of 250
ESSVE Decking screw HDS Pro with drill point, hidden fixing 4.8 x 60 mm A4, pack of 250
ESSVE Collated decking screw 4.2 x 42 mm A4, pack of 1000
ESSVE Decking screw Classic 4.2 x 42 mm A4, pack of 250
ESSVE Decking screw HDS, hidden fixing 4.8 x 60 mm A4, pack of 250When should you use screws made of stainless steel A2?
With screws made of stainless steel A4 you can never go wrong – they are always the right choice. In many cases, however, a screw made of the slightly less resistant stainless steel A2 in corrosion resistance class C4 is sufficient. A2 screws are usually cheaper than A4 screws.
Here are a few examples where you can use screws made of stainless steel A2.
Decks by a lake
The fresh water in lakes and rivers does not contain as much salt (chlorides) as the sea – and it is salt that reduces the corrosion resistance of screws. By a lake or river, A2 stainless steel screws are therefore sufficient. By the sea or a swimming pool (chlorinated water), however, choose A4.
Ground-level decks
Moisture from the ground the deck stands on increases the risk of corrosion. In this case, therefore, use screws made of stainless steel A2 or A4.
Large and high decks
Large and high decks are exposed to movements that can put stress on the screws. Screws made of stainless steel A2 are sufficiently ductile, so they are a good choice for large and high decks.
Choose the contractors' favourite screw
ESSDECK Max is a decking screw that quickly became a favourite with contractors. It is made of strong steel and has a small, discreet head and high clamping force. It is made of stainless steel A2 or acid-proof stainless steel A4.
ESSVE Decking screw ESSDECK MAX 4.8 x 55 mm A2, pack of 250
ESSVE Decking screw HDS Pro with drill point, hidden fixing 5.0 x 75 mm A2, pack of 250
ESSVE Collated decking screw 4.2 x 42 mm A2, pack of 1000
ESSVE Decking screw CLASSIC 4.2 x 55 mm A2, pack of 250
ESSVE Decking screw HDS 4.8 x 60 mm A2, pack of 250
Deck maintenance and cleaning
Removing ice from the deck
In winter, de-icing salt is often used on decks. Remember that de-icing salt contains aggressive substances that penetrate the wood and also damage the screws. If you use screws made of stainless steel A2 or A4, you avoid corrosion that can destroy the deck joints.
Cleaning the deck
The chemicals in cleaning products damage the screws that hold the decking boards. On A2 stainless steel screws and A4 acid-proof stainless steel screws, however, cleaning chemicals are not as harmful as on lower-quality fasteners. If you plan to clean the deck with cleaning products, both an A2 screw in corrosion resistance class C4 and an acid-proof A4 screw in corrosion resistance class C5 are therefore a good choice.
And what about the screws in the load-bearing structure?
Screws in the load-bearing structure, i.e. the screws used to build the substructure, are often less exposed to corrosion because they are not subjected to the same stresses as the screws in the decking boards.
However, if you are building a timber deck in a particularly demanding environment next to a swimming pool or close to salt water, use stainless steel screws in the substructure too.
ESSVE offers a wide range of stainless steel construction screws. To install the joists, use the W (WAF) construction screw – with a construction screw you do not need to pre-drill a hole or use a connector. Alternatively, you can also install the joists with stainless steel connector screws together with stainless steel connectors.
Stainless steel screws and connectors
Recommended articles
A deck by the pool!
If you are building a deck with a swimming pool, it affects the design, the choice of wood and the choice of screws. Find out all the details before you start building.
Deck maintenance
A step-by-step guide to deck maintenance. Preparation, advice on washing and other tips for the best result and a long service life of your deck.
Avoid the most common mistakes
We have put together a list of 7 problems that often arise when building a deck, and the best ways to avoid or solve them.
The contractors' favourite screw
Read how the ESSDECK Max decking screw quickly became a bestseller. Perhaps you should choose it for your project too.
The information in this guide is for guidance only. Follow the manufacturer's technical data sheet and the applicable standards; if in doubt, contact us.