Can or Should You Put 2 Layers of Drywall on The Ceiling?

A friend of mine actually discovered that they had two layers of drywall on their roof after removing their air duct. As you can imagine, my friend was surprised to find this out. I myself had never heard of putting two layers of drywall on the ceiling before!

The main reason why people like to put 2 layers of drywall on the ceiling is for extra protection and soundproofing. In many cases, the top layer of drywall is also fire-resistant. If you live in an area prone to wildfires, this could be an important consideration.

Another reason to install two layers of drywall on the ceiling is for additional insulation. This can help keep your home cooler in the summer and warmer in the winter.

Is it possible to have two layers of drywall on the ceiling?

Yes, it is, and it’s even a common practice for warehouses that need better stiffness for their housing unit.

You may also notice that houses, based on their local codes, are required to have a 2-hour fire rating and will most likely have two layers of drywall on the ceiling.

It’s also used in drywall repairs to save time. If you already have a layer of drywall installed and are looking to patch it up, try putting another layer instead of replacing it.

This will significantly cut back the time you spent on the project and gives additional benefits to your home!

Benefits of two layers of drywall on ceiling

Sure, it’s nice to know that having two layers of drywall on the ceiling isn’t that weird but there’s a lot more that you can gain from having two layers of drywall.

Increases fire resistance

Water is a primary component of drywall. Once a fire occurs, the moisture contained in the drywall will react, slowing down the transfer of heat and likewise, the spread of fire.

If you have a type X drywall (⅝ drywall thickness) then you’ll have at least 45 minutes of fire protection, having two layers of that will give you 2 hours at most.

Sound Insulation

If you’re only relying on two layers of drywall then it’s not gonna soundproof your entire room, it’s just gonna help with reducing it.

Usually, two layers would require the help of green glue or noise-proofing compound, to completely block out the sound.

Even then, you still have to worry about sockets and the like because it acts like air gaps, letting the sound flow freely.

Impact Resistance

This is an essential factor for those with workshops since slip-ups with heavy equipment can easily damage drywall.

Tall Builds

One layer of drywall wouldn’t be able to handle very tall builds. Hence, they use two layers just to add to the stiffness.

It’s most commonly found in warehouses and other tall partitions. Without having that extra layer, the building will slowly crumble, especially during the event of an earthquake.

Alternative Repairs

Instead of replacing new drywall, you can try to add another layer. Not only will you get all the benefits mentioned on this list but it will also save you time.

After all, you will already be installing a fresh drywall layer whether you remove the old layer or not.

This only works if your old layer doesn’t require removal.

How to install two layers of drywall on the ceiling

Step 1: Inspection

Now is the perfect time to see if there are any faulty plumbing or protruding wires that may get in the way of our project.

If there’s any, you can add furring strips to even it out, making it flat. After all, wobbly ceilings don’t look too ideal.

Step 2: Preparation

Always mark out everything about your project. Make sure to know where to cut out pieces. You can do it by directly drawing on the drywall.

If you’re in need of time, check and see if you can hide joints in bulkheads, you can save a lot of time fire taping it instead of spending a lot of time and effort on finished tapers.

After you’ve marked everything out, cut the drywall into your desired length. If you’re having trouble, check out this article about cutting drywall.

Step 3: Ceiling Joists

You need to know where these are located. After finding one, mark it out using a pencil or a marker.

If you’re unsure of where it is, tap a hammer on the ceiling and check for any solid sounds as there are wood framings.

Step 4: Lights, Vents, and Everything Else

This time, you’ll mark out where you plan to put the lights and/or vents on the ceiling. Make sure you’re marking the drywall that you plan to put in that area.

When you’re on the first layer, you can mark it a little bit bigger than needed. You only need the precise cut on the second layer.

Step 5: Smoothing (Optional)

This step is for those who want to make their joints as tight as possible, especially on the scored/cut edges.

Smooth out the rough edges of the drywall using a surform tool by sanding it down, this will make your joints tighter.

Step 6: Adhesive and screwing

Apply adhesive on the ceiling joists of the first drywall. It’s better if you start on corners, it’s easier to adjust the whole build that way.

If you’re a beginner, make sure to test out the sheet first by raising it to your desired position. Put on the adhesive once you’re confident in the placement of the sheet since it dries after 15 minutes. Lastly use drywall screws and screw them into the ceiling joists for best results.

Step 7: The first layer

If you’re alone and don’t have any sort of lift, use a t-brace to aid you in this process. Slide it into your desired place, the tapered edges should be facing the floor.

Next, attach the drywall to the joists. When you insert the fasteners, they should be 0.95 cm away from the edge, preferably 18 cm apart from each other.

There should be a 30 cm increment when installing fasteners along the interior joist.

When installing the next row, use half of the size of the first row as a way to stagger the seams, strengthening them.

Step 8: Repeat

Just repeat the process until you’ve completed the whole ceiling. After that, the first layer should all be done.

Once it’s done, you can go ahead and cut out all of those marked holes that you have. Since this is just the first layer, you can make the hole a bit larger.

Step 9: The second layer

If you want better soundproofing, you can apply green glue between the first and second layers before continuing.

Next, make sure you have screws that are twice the length of your sheet’s thickness. That way, your screws will go all the way through the second and first layer, and to the joists.

Make sure to stagger the seams and smooth out the edges, just like your considerations on the first layer.

After that, cut out the marked holes to their perfect sizes. Once you’re done with that, you can sand down the edges to make it smooth.

Step 10: Joint Compound

Apply joint compound and make sure it fills the screw heads. After that, use paper joint tape on all of the joints and ceiling corners.

Press the join tape onto it using a wide putty knife and joint compound. Repeat this multiple times until you have a smooth surface. Sand down in between layers, if needed.

Things to consider when you apply double or 2 layers of drywall

The room size

Having two layers sounds excessive enough as it is, but the problem comes when you only have a small room to work with.

Adding another layer will considerably lower the space of your room, ask yourself if lessening it will greatly inconvenience you before adding another layer.

Ducts, outlets, and other holes

If you’re applying a second layer for the purpose of sound insulation then you better mark these areas out for it to be effective.

If it’s not properly dealt with, adding a second layer may be useless since there will be a space where sound travels freely and these are the holes and ducts on the ceilings.

Your already existing drywall layer

Don’t push it if you’re ceiling is in dire need of replacement. This will cause more problems than it will solve.

In some cases, your old ceiling may already be sagging. While this doesn’t need to be replaced, it’s better if you even everything out before you can apply the second layer.

Your skills

This is an important aspect since it ensures the quality and overall safety of your build, especially if this ceiling is on the first floor.

An improperly installed screw may ruin all of your hard work, it can easily de-attach itself once you start hanging a ceiling fan or jumping on it when you’re on the second floor.

So, if you’re looking to save money and DIY the second layer then make sure you’re qualified for the job, you’ll be spending a lot more on accidents otherwise.

Conclusion

While it may just be a requirement to some areas due to the local code, it shouldn’t be the main reason why you have a second layer! After all, it adds numerous benefits!

It’s also a great way to save money and time if you’re not too keen on replacing the whole first layer with a new one.

Even so, you should still make sure that you’ve done the proper considerations and preparations for the job.