Predrilling Holes

 Is it necessary to pre-drill wood screws?

It’s not absolutely essential that you pre-drill them, but it is recommended by most professionals that you do.

 

If you don’t pre-drill the wood then there is a much higher chance of the wood splitting when you try to put in the screw because you’re putting a lot more pressure on the wood around it which causes it to weaken and crack.  So pre-drilling the wood is worth doing as it greatly reduces the risk of splits and cracks in the wood.

 

If you’re using a solid type of wood then screws will hold the best and for far longer if the wood has been pre-drilled with either pilot or clearance holds before you attempt to insert the screws.

 

Clearance holes are holes that are drilled into the top of the wood to prevent jacking.  The clearance hole needs to be large enough that the screw will fit through it without the thread biting into the wood.

 

The correct way to pre-drill wood screws

When pre-drilling wood screws it’s important that you do it properly.  The steps below show you how.

 

1. Make sure your drill is in good working order and is safe to use.

2. Insert the appropriate drill bit into it for the size of hole you need to make.

3. Use a pencil or something similar to make a mark where your hole is going to be.

4. Select level two on your drill.

5. Making sure that your drill is straight and level (so that you are drilling at 90 degrees), drill the pilot hole through the top deck board and into the joist underneath.

6. Swap your drill bit for a brad point drill bit.

7. Change your drill speed to level one.

8. Again make sure that you have the drill angled so that it is straight and level for where you are drilling, then insert the screw while ensuring the head of it is flush with the board.

 

There are a few other important factors to consider -

l Your pilot hole should never be any smaller than the minor diameter of the screw.

 

l If the wood is hard or if the the threads of the screw are quite deep then make the pilot hole a bit bigger than the minor diameter of the screw, but not too much.  If the wood is soft then make it a bit smaller.

 

l Always make sure that you enlarge the pilot hole to make a clearance hole so that the screw will pull the two pieces of wood together firmly.  A clearance hole should be no smaller than the major diameter of the screw.  If you don’t make a clearance hole then there will be a gap between the pieces of wood that glue would be ineffective at filling as the gap would be too big - glue should only be used to fill in small gaps with - usually those no thicker than a sheet of paper.

 

How to insert deck screws

When you are inserting deck screws it is important to do them the correct way, which is as follows:

 

1. First of all, you’re going to need a deck screw kit that contains stainless steel screws that are no less than 2.5” long (see below for which are the best deck screws).

 

2. Place your deck board onto the frame and mark it to show the location of the baseboards underneath.

 

3. Select the lowest speed setting on your drill so that you have as much control over it as possible and insert the deck screws around one inch in from the edge of the board.  It’s important not to go too near the edge or there’s a chance of the boards splitting.  When inserting the screws make sure you drill them in straight and use your weight on the drill to screw them down firmly.

 

4. Make sure that the head of the screws are level with the board, or just slightly deeper into it.

 

5. Try to space the screws out on each board so that they’re an equal distance apart.  This will help to ensure that they are not noticeable and that they blend in with the boards.

 

What length screws should I use?

Usually, deck screws are around 8-gauge and have a length of no less than 2.5 inches so that they have a sufficient size to screw the decking boards down onto the framework.  However, a lot of professionals use screws that are around 3 inches long for extra security and to protect against the pressure of boards that shrink or warp.

 

Nails or screws?

You  never use nails for decking as they can easily pop out of the wood and can be dangerous.  Although they are often cheaper than screws they rust easily, whereas screws don’t, and screws also give a much firmer and more secure finish to the decking.

 

How deep should deck screws be?

Deck screws should generally always go at least half way through the decking boards to give a firm hold.  Also, it’s important to remember that they should always be around one inch in from the edge of the decking board and never less or your wood could split.

 

Do you need to countersink deck screws?

Usually, when you insert a screw, you don’t screw it in any further once the head reaches the board.  However, countersinking is when you insert the screw a little deeper so that its head goes down into the wood some, instead of only being flush with the top.  It is generally okay to countersink deck screws.

 

How many deck screws to use on a 6-inch board?

For 100sqft of deck, using 6” boards and 16” joists then you would probably need around 350 screws.

 

It is advisable to use two screws every time a decking board and a joist cross and also to use three screws when fastening the boards to the rim joists.

 

Best deck screws

Deck screws really need to be able to cope with all different kinds of weather - including a lot of rain - so screws that are resistant against corrosion are essential.  The best ones to buy are galvanized or stainless steel deck screws.

 

Amazon has a great option available for purchase online - Eagle Claw Stainless Steel Deck Screws.  (affiliate link)

 

They are made from 350-type, 304-grade stainless steel which makes them perfect for a number of different jobs - from fencing and decking, to general wood-working projects.  They are corrosion-resistant and can be used for all types of wood - hard, soft, and pressure-treated.