How Do I Prevent Screws From Splitting Wood?

We might think that we are a confident DIY-er, but it doesn’t take much to break that confidence. Certainly it doesn’t take much to cause huge frustration, particularly where we encounter a problem that a trade expert would be able to prevent or deal with much easier. A classic example of this is splitting wood with a screw.

When you are fixing some shelves or making up a bookcase you will very likely be required to screw into some wood. Often we are building flat-pack furniture such as a bed, a set of drawers or a cabinet. Screwing into wood is a very common exercise and is also perhaps the most frequent example of how a project can go wrong. Splitting wood when you screw or drill into it can be an expensive error if you have no replacement material, it can irreparably damage the unit you are constructing and it can also cause you personal injury. So here are some useful tips to help prevent this happening, to make sure you complete your DIY project and to avoid the frustration and expense of damaging your materials.

Tips on how to prevent screws from splitting wood

Use the right type of screws – First and foremost you should make sure you are using the right type of screws for the exercise. Seek advice as necessary, but check that the screws you are using have the best features to avoid splitting the wood. Wood screws have a sharp point and a thread to grip into the wood when you drive into it, this should avoid splitting the wood, but you also need to make sure you have the correct size and shaft length so you are not putting excessive force on the wood.
Good quality wood – If you are using cheap wood, or a wood type that is clearly unsuitable, then this is more likely to lead to damage and splitting. You should also make sure that your wood is stored flat and in dry conditions, any wood that is warped or carrying excessive moisture could lead to splitting.
Correct set-up – The layout of your drilling or screwing exercise is critical in how successful it will be. Make sure your wood is balanced so that the load is evenly spread, ideally with support on either side of where you intend to drive into the wood. Putting excessive force on the wood with pressure on one side only, for example, could lead to splitting.
Tools – Cordless drills are one of the most popular and convenient DIY tools, they are great for a variety of applications, but they are very powerful and you need to be confident in how they operate and how you should control them. Make sure you are using the right setting and that your drill or screw bit is properly located and secured.
Drill a pilot hole – Perhaps the most critical tip in avoiding splitting wood is this one. Using a drill bit, mark a small hole in the wood and then change to a screw bit. Using the pilot hole as a marker, drive the screw into the hole. The pilot hole you have created reduces the pressure on the wood and gives the screw and thread something to grab onto. This should enable you to drive the screw comfortably into the hole. There are some accessories for a cordless drill which have a pilot hole drill bit on one end and a screw bit on the other end, so for convenience in this type of application you just have to remove and reverse the tool, rather than swap between different bits.
Part screw into the hole – Once you have a pilot hole you can screw into the wood, but only screw partly into it at first. Stop to see if the screw is being driven in okay, sometimes you can tell if the wood is going to split, so you should stop and reverse the screw out to avoid damaging the wood, and assess what the cause is. If everything looks okay, you can continue to drive the screw fully into the wood.
Screw location – You should avoid screwing into the wood at the end or edge of the piece, as this can create too much pressure on the wood. Ideally you should be screwing into the wood at least 15-20mm from the end.
Not too deep - Of course you have to screw sufficiently into the wood to secure it as per the assembly instructions or the screw length, but avoid screwing too deeply into the wood. This can cause the grain to weaken and break down the wood, leading to splitting.
Lubricate – Adding a small amount of lubricant, such as oil or WD40, reduces the friction that is created by the screwing action. This is particularly useful for thinner wood.

Alternative screwing methods to avoid splitting

While the method of using a pilot hole is the best way to avoid wood splitting, there are a couple of alternative methods which are known to work and can be used on the right type of materials:

Reverse – As an alternative to pre-drilling a pilot hole, if you set your cordless drill into reverse, but put manual pressure on it to over-ride this and force the screw into the wood, this naturally creates a starter or pilot hole. Using the reverse setting reduces the force in the crucial initial stage, and then your manual force is sufficient to drive the screw into the wood.
Angle – If you drive the screw in at an angle the wood is less likely to split. This is because the screw will hit multiple grains of wood, which helps to spread the pressure and reduces the likelihood of splitting.

Contact MB Direct for advice on screwing into wood

If you need further advice on the right type of screws and fixings for working with wood, or advice on how to avoid splitting your wood, then contact our experts at MB Direct today.