HEATWAVES AND PLASTERING
One of the most common problems that we deal with, particularly during summer is tape cracking or lifting. We refer to this as tape dry out.
Base bond which is predominately used for taping here in Australia is a chemical set compound. When mixed with water it starts the process. Water is necessary to actuate the chemical bonding process, but it is crucial that there is enough moisture in the compound at the time that the setting takes place, which is normally around 5 minutes prior to the compounds set time - 40, 60 or 90 minutes. If there is not enough moisture at that time the compound will dry but not set and therefore will have a weakened bond.
Normally it is easy to tell when this has taken place as two things occur. Firstly, the tape pulls out very easily and secondly. it will be dusty under the tape. Usually the tape appears to be cracked on the edges and when you pull them out the above has occurred.
These days with the rise in the use of taping banjos and boxes the problem has become more prevalent. This doesn’t mean that they can't be used, but it is the applicator's responsibility to determine the suitability of any product used. High heat, humidity and wind can drastically change the performance of a product, and can even result in complete failure of the product. We manufacture a range of products with various set times and care should be taken to choose the right product for the conditions. As a rule of thumb, for base and cornice cement if in any doubt, choose a shorter set time or consider using a ready-mix all -purpose compound such as 4T or Hamiltons, or a taping compound (first coat only) such as Pro Plaster lightweight taping compound.
By Perry Richardson
Founder & Managing Director of Pro Plaster Products