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Unit: Lay flat vinyl

LMFFL2301A: Install lay flat vinyl floor coverings

Section 4: Laying techniques

Cold welding

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Audio for slide 1 (mp3 |6|KB)
Cold welding is also called chemical welding, because it uses a solvent to fuse the two sides of a seam together.

The process is applied widely to carpets and PVC products in all sorts of applications - but in resilient floors it's generally only used with cushioned vinyl that isn't suitable for heat welding.

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You should always wait until the following day after installation before cold welding the seams.

This allows the adhesive to set and gives the moisture from the adhesive time to evaporate.

Some manufacturers recommend a full 24 hours before cold welding.

Set out below is the general procedure for seam sealing with a PVC cold welding liquid.

Typically, this product comes in a tube and is applied through a steel needle attached to the tube's nozzle.

However, there are variations on this technique, so you should always follow the specific instructions provided by the manufacturer.

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General procedure

  1. Place masking tape over the seam and press it down firmly.

  2. Cut through the masking tape over the join between the two sheets using a straight knife.
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  1. Press the needle of the tube firmly into the seam and pull the tube along the join.

    Control the flow of liquid so that a 5 mm wide glue line appears on top of the masking tape.

  2. Wait about 10 minutes for the glue to bond and then pull the masking tape off.
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Learning activity

Audio 5 (mp3 |6|KB)

The link below will take you to a video clip produced by Johnsonite Flooring on how to do a cold weld.

Cold weld installation video

Watch the video and then answer the following questions:

  • What tool does the installer use to press the masking tape down firmly onto the flooring?

  • What angle does he hold the tube at while he is applying the cold weld liquid.
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