Apply jointing strip to an inside corner

Having trouble applying joint tape in an inside corner? No worries! Jérémy Poupart explains every step you need to follow in this video to achieve a smooth and straight corner using Beissier’s Prestonett J ready-to-use joint treatment compound.

Six key steps to apply joint tape in an inside corner

The term “inside corner” or “interior angle” refers to the junction where two walls meet. This angle ranges between 180 and 360 degrees, contrasting with the outside corner. In architecture or construction, the term “cueillie” is used to describe this inside corner, which is formed by the intersection of two planes (such as a wall and a ceiling, or two walls).

Before you start applying the compound, check your surface. It must be sound, dry, clean, and free of loose material. If you notice any holes, fill them with PRESTONETT INTERIOR FILLER or “Prestonett Reboucher” filling compound and ensure the screws are properly driven in. In the project shown in this video, Jérémy Poupart uses Prestonett JP, a ready-to-use joint treatment compound. This ready-mixed solution is convenient as it eliminates the preparation step: you can use as much as you need without having to transport water to the site.

Recommended Tools

We recommend using two knives (one 20 cm and one 10 cm) as this will help you apply the compound effectively and achieve smooth finishes without lifting, blistering, or micro-bubbles.

You can also use a right-angle knife specifically designed for inside corners, which will make applying the compound easier. Equip yourself with a reinforced tape for a sharp, straight corner, or paper tape if preferred.

Method for applying the joint tape

The first step in applying joint tape in an inside corner is to carefully apply the compound to the angles on both sides using your two joint knives or your right-angle knife.

Next, cut a piece of reinforced tape with a drywall shear and position the tape against the corner. Then press it into place on both sides of the angle and apply a second, thin layer of Prestonett JP over the wet compound. Repeat these steps for the inside corners of the walls and ceilings in the room.

After letting it dry for 6 hours, cover the tape with a wider finishing coat than the previous layer for a complete smoothing.

Finally, let it dry for 24 hours, then sand it with 150-180 grit sandpaper by hand on these small, delicate surfaces. Don’t forget to dust off before painting!