Swell Sauna Resource Page

Outdoor Waterproofing / Silicone Sealing Verification for ECO4 & Retreat4

Use this page to verify that your ECO4 or Retreat4 sauna roof join has been siliconed correctly before the sauna is left exposed to outdoor weather.

IMPORTANT — Roof Access & Final Weatherproofing

1. Electrical work must be completed before final roof sealing.
The electrician requires access to the roof/ceiling area to complete the electrical installation.

2. Who completes the final sealing?

Installer + electrician on site together: Electrician completes electrical work → installer completes final silicone sealing.
Electrician finishes before installer: Installer completes final silicone sealing before leaving.
Installer finishes before electrician arrives: Do not complete the final roof sealing. Cover the sauna securely with a waterproof tarp until the electrician attends. Once electrical work is complete, the electrician completes the final silicone sealing steps before leaving.

⚠️ NOT WEATHERPROOF UNTIL SEALED
If there is a delay of several hours or days between installation and electrical work, the sauna is not considered weatherproof during this period.

It must remain completely protected from rain with a waterproof tarp until the electrician has completed their work and the final silicone sealing steps have been completed.

Simple rule

Electrical→Final Silicone Seal→Weatherproof

What the waterproofing should look like

Use the photos below to check the before, after and fully sealed stages.

Step 1 — Not weatherproof

Before silicone

This shows the roof join gap before silicone has been applied. The sauna must not be considered weatherproof at this stage.

Roof join after silicone groove and light silicone film over timber

Step 2 — Weatherproofed

Silicone applied

The crack/groove has been sealed with silicone, with a light silicone film across the timbers in that zone.

Swell sauna fully sealed and weatherproof

Step 3 — Fully sealed

Ready for outdoor exposure

Once the silicone step has been completed correctly, your sauna is fully weatherproof and can be outside uncovered.

Shingle overlap silicone step

Lift the overlapping shingles and apply silicone underneath the overlap.

This helps seal the shingle overlap area so water cannot track underneath the roof shingles.

Important: The yellow protective film is still in place in this photo for demonstration purposes only and must be removed during installation.

Lift overlapping shingles and apply silicone underneath the overlap

Silicone sealing video

Please follow the steps in the video below on how to correctly silicone the roof join gap of your sauna.

Final check: If the groove has not been sealed, or there is no light silicone film over the timber in that zone, the sauna is not yet fully weatherproof.