TT - Application on Vinyl
Craftsman Guide / Wet Rooms Application: Vinyl Sheet. Instructions for preparation, skim-coating, floor drains, and application on existing vinyl sheet membranes.. 💡 Important for Vinyl Sheeting in W…
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by tomas martinsson
Craftsman Guide / Wet Rooms
Application: Vinyl Sheet
Instructions for preparation, skim-coating, floor drains, and application on existing vinyl sheet membranes.
💡 Important for Vinyl Sheeting in Wet Rooms:
The final finish in bathrooms with vinyl sheets on both floors and walls depends heavily on meticulous preparation. Overlapping seams between floor and wall upstands mean internal corners will naturally remain somewhat rounded. However, thorough substrate preparation minimizes this radius and creates a clean, professional overall aesthetic.
The final finish in bathrooms with vinyl sheets on both floors and walls depends heavily on meticulous preparation. Overlapping seams between floor and wall upstands mean internal corners will naturally remain somewhat rounded. However, thorough substrate preparation minimizes this radius and creates a clean, professional overall aesthetic.
1. Inspecting the Condition of the Vinyl Sheet
Before starting any work, the condition of the vinyl sheet must be thoroughly checked:
• The membrane must not have any tears, blisters, voids, or loose sections.
• Check carefully around the floor drain: Any air pockets or delamination around the drain must be corrected; otherwise, the skim coat and cement will crack over time. Ensure corner upstands are fully bonded and rigid.
• Substrate Rigidity: A soft, cushioned vinyl sheet is not recommended since microcement is only as hard as the substrate underneath. Soft vinyl increases the risk of indentations and point-load damage.
• Check carefully around the floor drain: Any air pockets or delamination around the drain must be corrected; otherwise, the skim coat and cement will crack over time. Ensure corner upstands are fully bonded and rigid.
• Substrate Rigidity: A soft, cushioned vinyl sheet is not recommended since microcement is only as hard as the substrate underneath. Soft vinyl increases the risk of indentations and point-load damage.
↳ In dry areas, heavy furniture may leave indentations if the vinyl is soft. Forcrete handles this better due to its epoxy matrix, but a completely rigid substrate is always optimal.
2. Substrate Preparation & Skim-Coating
To level transitions and minimize rounded coved corners, thorough skim-coating is required (internal corners will naturally retain a slight radius due to the wall upstand):
• Priming: Prime the sheet overlaps and upstands with an approved bonding primer for non-absorbent substrates (such as Ardex P4 or an equivalent grip primer).
• Skim-Coating: Build up and flush out transitions using a cementitious repair mortar (e.g., Ardex A46) or a rapid-setting moisture-resistant tile adhesive. The goal is to reduce the rounded profile as much as possible prior to microcement application.
3. Floor Drain & Drain Grate Handling
When applying microcement over vinyl sheet flooring, installing a new metal drain grate is recommended to eliminate the plastic cover. This provides a cleaner finish and prevents the lid from abrading the sealer.
• Grate Selection: Choose a dedicated microcement grate (such as Purus Sun) or a mosaic grate. These offer a low profile (approx. 3–4 mm) and minimize the required adhesive thickness.
• Bonding: Bond the frame using an approved moisture-curing assembly adhesive (e.g., Tec7).
• Leveling: Trowel the repair mortar or adhesive flush with the top edge of the grate frame before applying microcement.
• Bonding: Bond the frame using an approved moisture-curing assembly adhesive (e.g., Tec7).
• Leveling: Trowel the repair mortar or adhesive flush with the top edge of the grate frame before applying microcement.
Important Note on Floor Slope & Full Skim-Coating:
If the floor has a steep fall, localized leveling around the drain frame is sometimes sufficient. However, if the slope is slight, leveling only around the drain risks compromising the fall.
For an optimal and uniform result, we strongly recommend priming and scratch-coating the entire floor. This ensures uniform porosity across the entire area during microcement application, preventing color variations and patchiness.
If the floor has a steep fall, localized leveling around the drain frame is sometimes sufficient. However, if the slope is slight, leveling only around the drain risks compromising the fall.
For an optimal and uniform result, we strongly recommend priming and scratch-coating the entire floor. This ensures uniform porosity across the entire area during microcement application, preventing color variations and patchiness.
4. Tips for Internal Corners & Crisp Finish
When vinyl sheet covers both the floor and walls, internal corners naturally retain a slight radius from the upstand.
To create visually crisp, straight corners, follow this process on the final finish coat:
To create visually crisp, straight corners, follow this process on the final finish coat:
1. Trowel Opposing Walls First: Apply microcement to the two walls directly opposite each other rather than working continuously around all four walls.
2. Mask for Straight Lines: Apply masking tape along the corners to establish a perfectly straight line.
3. Sand and Alternate: Once the first two walls are dry, sand them lightly. Apply tape over the newly finished surfaces and trowel the remaining two opposing walls.
This simple technique creates the visual illusion of a sharp 90° corner, noticeably enhancing the bathroom's final look.
2. Mask for Straight Lines: Apply masking tape along the corners to establish a perfectly straight line.
3. Sand and Alternate: Once the first two walls are dry, sand them lightly. Apply tape over the newly finished surfaces and trowel the remaining two opposing walls.
This simple technique creates the visual illusion of a sharp 90° corner, noticeably enhancing the bathroom's final look.
Next Steps: Microcement Application
Once the vinyl sheet has been inspected, leveled, and primed, proceed to reinforcement mesh and application:
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