When preparing to install cavity sliding doors, particularly at the framing stage, it’s essential to calculate the correct stud opening size. Builders frequently ask us how to ensure the frame is properly prepared for both single and double cavity sliding doors. Here’s a quick guide on how to do it right.

Stud Opening Calculation

For single cavity sliding doors, the formula is simple:
Door width x 2 + 60mm.

For double or bi-parting cavity sliding doors, the calculation changes slightly:
Door width x 4 + 60mm.

This ensures that the opening accommodates both the sliding panels and the space required for the pocket door system.

Frame Height for Phoenix (Standard) Cavity Units

To calculate the frame height for our Phoenix cavity sliding door units, use the following formula:
Opening height (sub floor to trimmer) = door height + 75mm.

This will give you the correct height for installing the unit. Our Triline interior sliding doorframes are designed to sit on the sub floor’s surface (whether it’s concrete, timber, etc.) before the floor coverings are laid.

Clearance Under the Door

One of the common questions we receive is about the clearance under the door. This gap is adjustable and ranges from approximately 10mm to 20mm. If floor coverings such as carpet, tiles, or vinyl are planned, this gap may be reduced accordingly.

For situations where you need more than 20mm clearance, you can pack the cavity door frame off the floor by the required amount before installation, or trim the door down to create a larger clearance.

Custom Openings for Specific Units

Each cavity sliding door system may have slight variations in its required opening sizes, depending on the specific unit being installed. For more precise information, visit the respective product pages on our website to get the exact dimensions for your project.

Phoenix Cavity Slider https://triline.net.au/product/phoenix/

Hercules Cavity Slider https://triline.net.au/product/hercules/

ProLine Cavity Slider https://triline.net.au/product/proline/

Zero Clearance Cavity Slider https://triline.net.au/product/zero-clearance/