Picture framing is generally caused through the failure to correctly pre-seal natural stone tiles prior to installation with a resulting migration of water through into the side of the tile from the grout lines.
The problem is associated with a number of factors and occurs after grouting.
1/ Cheap grouts: These should be avoided. ARDEX and CONSTRUCTION CHEMICALS are ideal as their grouts are colour stable and won’t bleed into most tiles and stone.
2/ Grouting wet stone: Natural stone tiles must be perfectly dry before grouting.
3/Grouting stone tiles before they have been adequately sealed:
This is the most common cause of problems. If unsealed, the stone will pull the grout in at its edges and stain the stone. An impregnating sealer should be applied to all stone tiles including the edges before Installation. It is important that the stone tiles are dry in the first place and that the sealer is left overnight to dry. We recommend the use of Stain-stop or Stain-stop plus from our Lithofin range of products in these instances.
Typical picture framing