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How To Remove Mastic From Drywall

Are you planning to remove mastic from your drywall, but you don't know how to? Good thing you checked this post out! We have thoroughly researched the steps of removing mastic from your drywall to get the best method for you!

Disclosure: We may get commissions for purchases made through links in this post.

  1. Use a heat gun to soften the mastic surface
  2. Scrape the surface and remove mastic as much as you can
  3. Apply a mastic remover
  4. Clean the area; allow it to dry
  5. Sand the drywall surface

We suggest you continue reading to know a more detailed process of removing the mastic from your drywall and how to make it look new again.

Replacement of old tiles, worker with hammer and chisel. How To Remove Mastic From Drywall

Proper Removal Of Mastic From Drywall

Removing mastic from your drywall is a demanding task. You have to put so much effort into removing it correctly and use the appropriate materials and tools to achieve spotless drywall. Additionally, work in a well-ventilated area and wear personal protective equipment to keep yourself safe from fumes and debris.

Preparation of repair the bathroom. Man Removing old tiles.

1. Use a heat gun

To soften the mastic surface, use a heat gun to warm it for 10 minutes. To prevent the mastic from solidifying as you do this step, we suggest working on two-foot, square sections.

2. Scrape the surface

Protect your hands and eyes by wearing gloves and goggles for this step. Scrape the mastic's surface to remove as much as possible. We recommend using a brush with stiff bristles for this. Pull the mastic out of the brush if it gets stuck. Continue the scraping process until no more mastic is left on your drywall.

3. Apply a mastic remover

Ventilate the area and wear a face mask. Remove the excess adhesive on your drywall with a mastic remover. It would be best to use a sprayer for application. Leave the mastic remover on your drywall for 10 minutes. Scrubbing pads work best to thoroughly remove the mastic.

And just a little tip, for this process to be hassle-free, we suggest you put rags on the floor to catch any liquid drips.

Click here to see Blue Bear mastic remover on Amazon.

4. Clean the area; allow it to dry

Using warm water and five drops of dish soap, you can create an excellent cleaning solution for your drywall. Clean your drywall using this solution with an old cloth. After it, you should rinse it using clean water and let the drywall dry itself for 24 hours.

5. Sand the exposed drywall surface

Use a sanding sponge to sand the dried surface to smoothen the entire drywall.

Click here to see variety-pack gradient sanding sponges on Amazon.

How To Repair The Drywall

To make your drywall flat and look new again, follow these steps:

Step 1

Scan the entire drywall to see all the dents and scratches the mastic has left and sand those areas thoroughly again. Blend a drywall compound after the sanding process. Ensure that you mix it well and do not leave any lumps. 

Click here for a drywall repair kit on Amazon.

Hand in glove with trowel applying wood filler before sanding

Step 2

Check all the holes, scratches, and dents that measure smaller than marble size and apply drywall compound to them. Seal all the holes with the mixture and provide a little more than the exact measure of the holes.

Then flaten and smoothen them using putty. Once you finish, let the mixture dry for 24 hours. Moreover, it would be best to supply drywall compounds to all the remaining dents and scratches as you wait.

Construction worker hand sanding and repairing a white wall.

Step 3

After waiting 24 hours for the drywall mixture to dry, you will have to sand the surface using sanding paper. Smooth the surface as flat and smooth as you can.

Alternative Methods Of Removing Mastic

Natural Removal Method

If you want to remove the mastic with a chemical-free solution, follow the steps below.

Soak the mastic in hot water

Soaking this adhesive in hot water makes it soft and reduces the grip, but this method will not work for all types of mastic. It is the safest way to perform compared to all mastic removal methods. The loosening of the adhesive will take 20 minutes up to an hour.

If you want to make a more robust solution, you can add vinegar to the hot water. Additionally, old and black mastic includes asbestos components. So, we suggest that you handle it wet as you remove it to avoid hazardous dust. For the safety removal, contact professionals.

Woman wearing red safety gloves removing wall tails in the kitchen

Remove the mastic

Once you finish making the mastic wet, you should break it off using a chisel and hammer or scrape it using a brush with stiff bristles after you chisel it. You can also use a putty knife for the scraping process.

If you remove the mastic from the floor, it would be best to use a brush with a long handle.

Using Chemical Solvents

If you want a stronger solution than hot water and vinegar, you should use chemical solvents.

Buy a mastic remover

You can buy a mastic remover from your local hardware stores. Mastic remover usually costs $100 per five-gallon or 19 liters. Choose a mastic remover that is produced from acetic acid or citrus. We can guarantee you that it is much safer than other available mastic removers.

Moreover, it would be best always to use mastic removers intended for wood. Use just the right amount to prevent the difficulty of bonding tiles for your future project.

Open the windows and doors

We suggest you open the doors and windows for better ventilation while using chemical removers. Wear a face mask, safety goggles, and gloves to protect yourself from fume inhalation and exposure.

Apply the mastic remover thinly

It will help if you transfer the mastic remover into a sprayer for better application. Similarly, if you don't have a sprayer available, you can use a clean mop to spread the mastic remover on the surface.

For your safety, don't stay for too long in the area after applying the mastic remover. In addition, before you use it, you should check the instructions on using it. It is always best to know the safety guidelines, especially if you are new to using one. 

And as we mentioned above, it would be best to put rags on the flooring to catch all the dripping liquids. 

Let the mastic dissolve

Letting the mastic dissolve usually takes from an hour up to 12. But for you to make sure, follow the manufacturer's instructions.

Scrape the mastic off

You can use a putty knife, brush with stiff bristles, or a razor scraper to scrape the mastic off.  Additionally, you can use a floor machine for quicker mastic removal. Dispose of the mastic properly.

Reapply & Clean the Area

Apply a thin layer of mastic remover once more to remove any remaining residue.

Using absorbent materials, wipe the mastic remover thoroughly. And if you are working on your flooring, you can use a wet vacuum for an easier process. 

Use a mixture of water and dish soap to clean the area and let it dry thoroughly.

Applied layer of adhesive for laying tiles. Excess glue was removed with a notched trowel

Where To Use Mastic

  • Interiors
  • Backsplashes
  • Drywall tiling
  • Wainscot of any room
  • Glass tilling
  • Low-traffic flooring 
  • Any walls where moisture is not present

Where Not To Use Mastic

  • High-traffic flooring
  • Mastic is strongly not advised for swimming pool tiling or with any water features.
  • Shower rooms or steam rooms
  • You cannot use mastic installed directly above flooring with radiant heat systems

construction worker uses a cemented trowel to apply cement glue to the stairs

Standard Substrata Approved For Mastic

  • Cement board
  • Concrete
  • Interior drywall (but if the drywall is painted, you must sand the surface first to roughen it or apply primer)
  • Exterior grade plywood

Standard Substrata Not approved for Mastic

  • Wooden blocks flooring or Parquet
  • Hardwood
  • Chipboard or particleboard
  • Lauan plywood

Mastic Vs. Thinset Mortar

Mastic and thinset mortar vary in terms of their adhesion, where you can utilize them, and, most importantly, their capability to seal and fill the gaps. 

Mastic

It is a fast-grabbing adhesive specifically for tiles. 

Pros

  • Mastic's adhesion is excellent because it is too sticky. And since it adheres well, it can reduce tile sagging on vertical exteriors.
  • You can store or keep the excess mastic for your future project.
  • The tile you used with the mastic is easy to remove.

Cons

  • The quick-grab characteristic of mastic suggests that you will experience difficulty correcting misaligned tiles.
  • You can only utilize mastic in dry areas. It is not recommended to use in high-moisture areas or where water is involved because it will not be able to adhere. 
  • Mastic has a pungent odor.
  • This tile adhesive is not recommended for tiles 15 inches or larger.

Thin-set Mortar

Thin-set mortar is a cheap tile adhesive. And you can buy this in three types: pre-mixed, dry, or wet. Also, there are two categories of thin-set mortar, the modified and unmodified versions.

Click here to see pre-mixed thinset on Amazon.

Silica sand, portland cement, and water retention mechanisms are the components that make an unmodified thin-set mortar. Similarly, modified thin-set mortar contains the same components but with additional liquid latex polymers. And that additional component makes the modified thin-set improve its strength and working time.

Pros

  • When you compare thin-set mortar to mastic, it is undoubtedly more substantial. And that is what makes the thin-set a better adhesive choice for horizontal applications.
  • The dry-mix thin-set type is cheap and the easiest to utilize. 
  • It has no odor, unlike mastic.

Cons

  • Unlike mastic, you should dispose of unused thin-set mortar.
  • This tile adhesive takes too much time to dry itself. And those tiles that you will install vertically will start to sag as it cures.
  • You will need elbow grease when removing both tiles from thin-set mortar.

Home renovation for young man dressing suit and mask for powder. How To Remove Mastic From Drywall

Wrap It All Up

There is no easy way to remove mastic from drywall. All you need is elbow grease, proper tools and materials, and a little patience to perform the process well. And that the removal process can take you two days or more.

We hope that this article helped you a lot. And if you want more of our assistance regarding your home projects and issues, you can check the posts below or visit our website to find more informative posts.

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