Do bed slats need to be screwed down? Yes, 3 reasons

3 reasons bed slats need to be screwed down

There are several reasons why bed slats should be screwed down, including:

  • Reduce or stop noises such as squeaks and creaks when tossing and turning while sleeping.
  • Make the slats stronger. You can see more tips in my article How to make bed slats firmer: 7 options here.
  • Save money by extending the life of the bed. This is especially true when children enjoy jumping and wrestling! 

What screws to use for bed slats

The best would be stainless steel wood screws, but that is overkill and a waste of money. Interior use screws are adequate unless you do not have climate control to remove humidity from the air in your house. 

Stainless is better for our bed frames where we live while in Thailand because we are off-grid and the humidity can easily hit 65% in our tiny home. So there are times when spending a little more money on quality strainless screws is worth the expense.

If humidity is not an issue then the cheaper zinc-coated silver wood screws are adequate for this project.

Check out our 312 lb test on four Ikea Luroy bed slats here.

Best screws for wood frame

The best are wood screws with flat heads (bugle/countersunk) with #10 thread diameter and have threads up to, or almost to, the head is the best for fastening bed slats to a wood frame because the slats are thin. 

These are hard to find so please consider the truss head type as they have a built-in washer and protrude very little above the slats. This increases the holding power of the screw while only slightly increasing the potential for damaging the mattress.

Pan washer or truss head style screw often used to make cabinets
Pan washer or truss head style screw often used to make cabinets

“#8 General furniture construction, cabinets, light construction. Good all-purpose. From 5/8″ to 3″ lengths. #10 General construction, heavy-duty furniture, outdoor projects, decks, lawn furniture, boat building, etc.”

McFeely’s, Wood Screw Size Chart with Applications

Best screws for metal frame rail

There are a couple of options here and both work well. One type holds the slats in place better, but it is more expensive so I am sure many readers want to know about both methods.

Unfortunately, MANY companies must be saving a few pennies by not running the threads all the way to the head of the screws. This is a problem because slats are thin, so the threads won’t catch the metal bed frame, rendering the screws useless. 

Screws with threads running to the head, or almost, are very hard to find. It took me too much time to find this example on Amazon

Self tapping screw with boring wings
Self-tapping/drilling screw with boring wings

Self-tapping metal screws

If you are not concerned with scratching the heck out of your arms, or you have a bed with no legs or close to the floor, you can save a few dollars and minutes. Just simply use self-tapping metal screws. 

These should be flat head (bugle, countersunk) type to prevent damage to mattresses. You can use any type of head if you are using a box spring because it is a box spring and no big deal if it gets a little dinged up.

The steps for this system of attaching slats to a metal bed frame are as follows:

  • Drill holes in the wood bed slats. Use a drill bit that is just slightly larger than the diameter of the screw threads.
  • Place the slat where you want it installed. Place a self-tapping screw into the hole and use a drill to drill the self-tapping head through the metal rail.
  • Tighten as much as possible.
3 advantages of self-tapping screws for a metal frame
  • Cheap
  • Easy and fast to install.
  • The only tool required is a drill and a bit that fits the screw head (in the US that is likely going to be a #2 Philips bit). I strongly recommend using a good quality bit for a good fit that allows you to tighten the screws well.

    Cheap ones don’t fit as well, cannot tighten the screw as much, and wear out very quickly. You can see high-quality ones by Bosh and they are cheap here at Amazon.
3 disadvantages of self-tapping screws for metal frame
  • Self-tapping metal screws protrude through the bottom of the frame and may catch the vacuum cleaner and damage it. The same for arms and hands reaching underneath the bed for stored items.
  • Tendency to wiggle loose over time and therefore requires monthly or semi-annual tightening.
  • Possible stripping of the threads that the screw creates in the metal frame. This can happen with over-torquing the screws, frequent tightening from maintenance, and the weakness from the weak and soft alloy metals used in most bed frame construction.

Carriage or machine bolts with lock washers and nuts

The best are carriage style with mostly flat heads and are actually bolts. You can see pictures here on Amazon. Bolts are much better because the screws or bolts have to penetrate the metal frame rail, which means if it is a screw it is dangerous to arms and hands reaching for items underneath the bed.

Machine bolts usually have a narrower thread and rounded head, which is less than optimum for this project. But there are much cheaper and readily available at any hardware store.

Using the best screws also comes with a more expensive price because the carriage bolts are more expensive than regular screws and each one needs a lock washer and a nut.

TIP: Make sure to purchase LOCK WASHERS. These compress when the nut and bolt are tightened so there is always tension on the nut. This prevents it from loosening over time with movement, which also stops noises as an extra bonus for the few extra dollars.

4 advantages of bolts and nuts for slats
  • Superior holding strength.
  • Unlikely to allow flex and wiggle in the slats over time as the bolts are compressed from the head and the bottom with the nut. 
  • Less likely to become noisy.
     
  • More compression strength because the nut and washer distribute the weight more on the metal frame compared to self-tapping screws.
3 disadvantages of bolts and nuts for slats
  • More expensive than self-taping screws.
  • More work. But the extra time required should only be 15 – 30 minutes depending on if working on a twin, full, queen, or king-size frame.
  • More tools are required. A drill bit for drilling metal that is slightly larger than the bolt thread size is required. Also needed is a wrench, adjustable wrench, or a socket set for tightening the nut.

Wood screw in a metal frame rail

This is another option that is faster and cheaper than carriage bolts, nuts, and washers. It is the same as using wood screws in a wood frame except that you need to predrill the metal frame with a drill bit that is smaller than the diameter of the threads.

Wood screws are tapered at the pointy end so the screw will easily start in the hole and the threads will tap the metal frame as the thread gets thicker. This is the least strong solution, especially for the long term.

If you are building your own bed slats or consider buying you should read my article How Thick Should Bed Slats Be? here.

Scott Boyd

How to attach slats to the bed frame

How to secure bed slats

If you are Ikea then you don’t, you just toss the roll of slats on the frame and stretch the straps to slide the end slats over the plastic stoppers. This does not fasten them to the frame and they will float on the metal support rails and sometimes fall through the bed!

There are better options, including:

Screw slats to the frame with one screw in each end

Read my section about how to screw down bed slats here. It has 5 important tips and below is a quote from this article:

“To screw down bed slats requires a drill with a Robertson or Philips bit, a 50-pack of 2”-2.25” interior tapered head (flat) wood screws (like these ones on Amazon, and wow these are hard to find on this huge website!), and two drill bits. In the first slat drill a hole a bit slightly smaller than the screw thread, countersink with a larger bit, add glue, install a screw, and repeat.”

Scott Boyd

This is a good method to prevent the slats from sliding sideways and north and south (headboard and footboard). 

Read my instructions here to see How to Replace Bed Slats for Twin-Size Beds here.

Screw slats to the frame with two screws in each end

This is the same as above except that we are adding two screws to each end. This makes the bed and slats stronger.

3 advantages of two screws vs one in slats

  • Reduces noise potential by reducing the possible racking motion of the slat since there is one screw closer to each edge of the slat. This holds the edges to the frame firmly so the ends cannot squeak during movement.
  • Increases the strength of the bed and slats including resistance to twisting. Think about… I don’t know, how about a broom hanging from a single nail on the wall? It swings easily with any sideways pressure applied. Drill a second hole in the handle about 2” below the first one and install a nail in it. It does not swing now. It is the same principle.
  • Distributes the weight across two screws, which has more holding power when the slats are sagging while with the weight of sleepers applied. 

Disadvantages of two screws vs one in slats

  • More expensive as there are twice as many bolts, nuts, and washers.
  • More time to complete the project.

Many people have asked me about using lumber and the answer is in my article Can I Use 2x4s for Bed Slats here.

Scott Boyd

Scott Boyd

I spend my days doing research, performance testing, and materials analysis and reporting my experience and test results to help people make decisions before purchasing expensive furniture.

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