Smoothing Uneven Walls Before Wallpapering

[Tomhanks]

Hi there!

What are the best methods or tools for smoothing out uneven walls before wallpapering? What can be done to prevent seams from showing after installation?

[FatimaandAhmed]

Hi, Tomhanks!

To get the best results when wallpapering, it's important to start with a smooth, even surface. If the walls are slightly uneven or have minor imperfections, a good approach is to use a skim coat of joint compound to fill in any low spots, then sand it smooth once dry. For more significant irregularities, a thicker application may be needed, followed by careful sanding. If the wall has old texture, such as orange peel or knockdown, sanding it down or applying a lining paper can help create a more even base.

To prevent wallpaper seams from showing, make sure to properly prime the wall with a wallpaper-specific primer, which helps with adhesion and prevents the paper from soaking up too much moisture. When installing, slightly overlapping the edges and then double cutting (trimming through both layers with a sharp blade) can create seamless joints. Also, pressing the seams gently with a seam roller but not too hard to avoid squeezing out the adhesive helps them blend in better. Taking the time to prep the wall properly and using quality adhesive will make a big difference in achieving a flawless finish.

[Tomhanks]

Thanks so much for the detailed reply, really helpful! Quick question, if I go with the skim coat method, do I need to use a specific type of joint compound or will the all purpose kind work fine for smoothing things out?

[FatimaandAhmed]

Glad it helped! And yes, all-purpose joint compound is perfectly fine for skim coating. It’s a popular choice because it spreads easily, has good adhesion, and sands down nicely once dry. If you're doing a final finishing layer or want something easier to sand, lightweight joint compound is also a great option. It creates less dust and can be a bit smoother to work with for that top coat.

Just avoid using the setting-type compounds (like the ones that say 45 or 90) unless you're really comfortable with them. They dry fast, which can be tricky for skimming large areas.

Whichever you choose, a couple of thin coats with light sanding between them will give you a nice, even surface for wallpaper. Let me know if you need tips on tools or how to apply it smoothly.

[Tomhanks]

Thanks, that clears it up a lot! Just wondering, after sanding the skim coat, do I need to seal the surface with anything before I start wallpapering? Or is primer enough on its own?

Also, any tips on making sure the surface stays dust-free right before applying wallpaper?

[FatimaandAhmed]

Hey, you're welcome! I'm glad I could help!

To answer your questions, after sanding the skim coat, applying a wallpaper-specific primer is definitely enough to prepare the surface. The primer helps seal the wall and creates a smooth, even base for the wallpaper adhesive to stick to, so you don't need anything else. Just make sure you're using a wallcovering primer because it’s designed to handle the moisture and ensure the wallpaper adheres properly. As for keeping the surface dust-free, you're on the right track! After sanding, give the walls a quick vacuum with a brush attachment to pick up most of the dust. Then, use a damp microfiber cloth to wipe down the walls, but don’t leave them too wet, just a light pass to catch the fine dust. Once everything’s dry, your walls should be nice and ready for the primer, and you’re all set for wallpapering.

[Tomhanks]

Thanks a lot for your help! That really clears things up.