What Screws Do I Need For Ikea Lack Shelves? Proof


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I bought IKEA LACK shelves around a month ago, and as fruitful as the end result was, I found it quite frustrating that there were no screws in the package. Had I known what size screws to use, I would have already arranged to have them by the time the shelf was delivered. Fortunately, the ones I had in my small spares box worked, and I want to share the results with you.

Ikea LACK shelves require 5 x #10 screws (3/16″) approx 2 inches (50mm) long for mounting to a drywall wall. 2 extra screws 1 3/16″ (25mm) long are needed to secure the actual shelf to the shelf bracket. The length of the screw is dictated by the wall material and thickness alongside the shelf weight.

In this article, you will learn all you need to know about preparing to mount the Ikea LACK shelf, including which wall material it should not be mounted on, how many screws you need based on the kind of wall material, and what type of screw will ruin your walls and the shelf.

But first, let’s look at the different properties of the perfect screw for the LACK shelf.

Ikea floating shelf bracket
Bracket in Ikea LACK shelf

Screw Material

In rare instances, one can use titanium or brass screws for extra strength, but in the case of mounting LACK shelves, there is no need for such unconventional screws. A regular steel screw is strong enough in most cases. As long as you use enough screws, you can secure a LACK shelf in the following wall materials:

  • Timber
  • Concrete 
  • Stone
  • Solid Hardwood
  • Metal

The number of screws you have to use will vary depending on the weight of the shelf and the material in which the screws are secured.

Screw Quantity

On average, you will need 5 to 8 screws to mount a LACK shelf. There are two weight classes of the shelf, and they dictate the screw requirements as much as the shelf function and the wall material. The weaker the wall, the more screws you need. The lighter the shelf, the fewer screws you need.

You can also get away with using fewer screws if they’re made from titanium, but whenever a LACK shelf collapses, it is not due to the screw material but because of the wall giving away or the mounting material biting into the shelf. 

If anything, the strength of the screw can damage the shelf when there is significant weight on said shelf. Therefore, it is safer to have more standard steel screws instead of a few very strong ones.

For the 33 lbs lack shelf, use a minimum of 5 screws and for the 44 lbs one, use eight. For every 10 lbs of weight beyond the 11 lbs starting point, add three screws. So, if your 33 lbs LACK shelf holds 11 lbs of weight, 5 screws should be enough. But if it carries another 10 lbs (21 lbs total), it needs 8 lbs.

If you find it appropriate to use more than 11 screws, though, you might be burdening the shelf beyond its maximum capacity.

The number of screws will be determined by how many timber studs you can fix into!

Wall material is another thing to consider because its limitation can’t be offset by using more screws or even stronger ones. For material that is not strong enough to hold up against high-thread metal screws, one must use wall plugs. It is wise to use wall plugs for almost every material except metal. You might not need the plugs if there is sufficient screw support.

Screw Support

In the context of mounting a floating shelf, there are two main ways a screw is supported. The first is to use actual screw support units to secure the screws more firmly into the material you’re drilling. The second is to use brackets. 

The brackets provide precision support by pointing out exactly where the screws need to be fixed, and they offer the length that makes balancing the shelf must easier on the supporting screws. You don’t need to buy a separate pair of shelf brackets for LACK, as it comes with its own suspension-support structure.

Screw Size

Given that you’re using IKEA’s own suspension support, selecting the right screw size and type becomes quite easy. You simply need to get the thickest screw that the supporting structure allows. Take the shelf brackets that come in the LACK package and examine the holes as seen in the picture below. 

Hole sizes in Ikea shelf brackets
Holes in shelf bracket

As you can see, the holes here have a 6mm width that registers as a 5.5mm for practical purposes. For smaller shelves, they would have a 4mm to 4.5mm hole. #10 screws would be the best for larger LACK shelves, while #6 screws would work for smaller ones.

The thickest screw that can go through the hole should be the one to choose. Before I get into the specific sizes that I found, let’s look at the reason you shouldn’t even try mounting with thinner screws.

Thin screws have a massive disadvantage where they can damage the wall and the shelf, alongside everything you place on the shelf. That’s why it is not worth it to risk using screws that are even slightly thinner than the bracket hole.

With that established, you can take your measuring tape and get the exact size that would work for your shelf. But if the LACK package hasn’t arrived, you can borrow my results.

In my picture, I have shown both countersunk and pan head screws. Either will work fine.

Screws needed for Ikea lack shelves
Screws needed for Ikea LACK shelves

The screw on the left in the picture above is approx 2″ (50mm) long.

Do IKEA LACK Shelves Come With Screws?

IKEA LACK Shelves do not come with screws, so you have to buy your own screws. You should take into account the wall material, the weight you expect the shelf to carry, and the size of the shelf before making your buying decision.

The picture below shows the instructions that come with a LACK shelf. Very unhelpful!

Ikea lack shelves instructions
INstructions that come with Ikea shelves don’t help much
  • The wall material – If the wall is made of material that a screw can bite through, you’ll need thicker screws or wall plugs to minimize the surface area and the “bite” of the screws. 
  • The weight carried – As long as your LACK shelf is not meant to carry more than 11 lbs of weight, you will not need to make unconventional purchasing choices when getting screws for mounting. Be sure to check out my article on how strong are Ikea floating shelves.
  • The size – The LACK shelves come in two sizes, mainly with a third option available in some stores. With each increment in size, 2 to 3 more screws are required.

Since the size, material, and number of screws is uncertain and partially dependent on the user’s house conditions, IKEA doesn’t provide the screws. Had the corporation decided to add generic screws to the package, you would have been charged for them, and they might not have worked well for your wall.

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Hole in Ikea shelf bracket for screws
Hole in the shelf bracket which stops the shelf from sliding off the bracket

The shelf support rails have these 7mm diameter holes in them as shown by the above photo. These holes do not have threads in them. They simply accept the screws that come through the face of the shelf as shown below.

Screws used for Ikea floating shelves
25-30mm screws used in the shelf face

Wall Material and Screws

On the subject of wall material and the degree to which it dictates screw choice, let’s explore some possibilities.

Wall MaterialNo. and Type Of ScrewsComments
Standard drywall with timber studs5 to 8 screws of 5mm width. Can varyThis number will vary depending on the location of your shelf and how many studs you are likely to hit.
Solid Hardwood6 to 10 steel screws of 4.8mm width at minimum (unless the hole is narrower)You’ll need plenty of screws to keep any specific screw from biting into shiplap or other wood wall covers/frames.
Metal5 to 7 steel, brass, or titanium screws of 4.8mm width (unless the hole is narrower)Thick metal frames provide support to the screws, so you don’t need as many of them to carry a bracket. 
Concrete5 to 8 steel screws of 4.8mm width (or 3.1mm width with wall plugs). Concrete is durable, but it doesn’t have the resolution to hold onto screws without getting bitten into. If the shelf doesn’t carry too much weight, this should not be a concern.
Heavy-duty drywall on its own16 screws of 5.5mm eachBecause drywall’s limitations put an impractical burden on the screws and fittings, it is not advisable to fix a floating shelf on drywall. But if you proceed with the decision, you would need to switch the brackets to ones that have thicker holes and a lot more space to fix screws on the wall. You might even need multiple pairs of brackets for a single shelf.
Table showing what screws to use for different wall types

Where To Get Screws for IKEA LACK Shelves?

You can order screws for IKEA Lack Shelves from Home Depot or any hardware store. Ironically, IKEA doesn’t have these screws. The Swedish furniture maker offers a spare-part purchasing option for smaller table screws and cabinets.

Your purchasing options are as follows.

  • Visit Home Depot, tell the staff you need “screws for a [insert weight] lbs floating shelf to be fixed in [insert wall material].” Make sure the screws are not thicker than 5mm.  
  • Get a screw set from Amazon. I recommend getting a larger package with multiple-size screws like this self-driving screw set. I have found these sets very useful and their greatest advantage is that it gives you more options when you’re ready to mount the shelf.
  • Hire a handyman – Finally, there is the option that I can’t speak for. You can call a handyman to help install the shelf. Such contractors charge you for the materials like screws but don’t make you shop for them. I’ve not really tried this option myself because such services would have been redundant.

What Size Screws For The IKEA LACK Shelf?

If you’ve decided to purchase the screws before the arrival of your LACK floating shelf, you have the advantage of being ready when the shelf arrives. At the same time, you can end up making a mistake in your purchase. With a screw set, you can experiment and err on the side of thicker and larger screws, but when purchasing specific-sized screws, you have to err towards the middle.

You should get #10 screws for the larger lack shelf and #8 screws for the smaller version. The screws should have a higher thread density and must be no smaller than 30mm. For heavy-duty shelving, you can use up to 50mm screws.

If the screws need to be thicker than 5.5 inches or longer than 50 mm, the shelf is under an impractical level of stress. In that case, it is wiser to switch from floating shelves to a cabinet.

How Do You Mount IKEA LACK Shelves?

Assuming that you have the #10 or #8 screws for the LACK shelf, here are the steps you need to follow to mount an Ikea LACK shelf.

Use a Level to Mark the Wall Before You Make Holes in the Wall

The marks should point where the shelf brackets will need to get fixed to the wall. This step is quite crucial because if the holes aren’t level, the shelf will be lopsided, and items placed on it will fall. If the holes are too shallow, the screws might not drive all the way through.

And if they aren’t spaced apart appropriately, the shelf isn’t going to be balanced. Ikea floating shelves can be cut if needed. See my article showing what’s involved. 

Use a Drill to Make Holes for the Screws

This is pretty straightforward, at least for me. As long as you don’t drill at an angle or too deep into the wall, the screw should be able to go through quite easily. Of course, the wall material itself can prove challenging to drill, but that’s a subject for another post.

Fix the Bracket to the Wall

Once the hole has been drilled, you have to fix the brackets to the wall, which requires fastening them with screws and screw-support like washers and plugs (if necessary). 

Place the Shelf in Position

Everything seems to be coming together now as you place the shelf where it is supposed to be. If you have done everything right, the holes on the shelf will align with the support position of the bracket so you can attach the two with secondary screws. Use your hand to drive the screws initially, then use a wrench to tighten them.

Final Thoughts – What Screws For Ikea Lack Shelves

IKEA Lack shelves are novice-friendly, so even if they seem complicated at first, there’s nothing to worry about. Get a set of #8 and #10 screws if you’re not completely sure which one will work, and follow along with the instructions included in the package or covered above. 

Derek

I'm the guy behind Woodwork Hubby! I have been doing woodwork and cabinetmaking for over 30 years so I decided to start this site to help educate others on what I have learned.

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