The final area we will be looking at which may need some maintenance work carrying out is renders. Renders may crack, degrade or debond over time due to normal weathering, impact or freeze/thaw attack. Your render may therefore have debonded last winter when we suffered with the terrible cold weather and it is important to carry out the necessary repairs now before we reach those winter months yet again.
How can I tell if my render has debonded?
Hollow or debonded render can be found by simply tapping the render. If it makes a ‘hollow’ sound then it may be coming away from the wall. In which case some maintenance work is required.
What you will need for the job:
1. External bonding agent
2. Cement: sharp sand mix: Ordinary Portland Castle Cement
The cement used for this type of job would be Ordinary Portland Castle Cement. The strength requirements of renders are widely varied and this particular cement is designed to be adaptable in performance to accommodate the requirements of the application.
Cement is suitable for use in all types of renders. Care should be taken to ensure that the surface to be rendered is clean and free from dust. Mixes for successive coats should neither be stronger nor thicker than the previous coat. Each coat should be allowed to cure for several days before a subsequent coat is applied.
Ordinary Portland Castle Cement is a cement which enhances sustainability through the use of carefully selected recycled raw materials, reducing the carbon footprint of the cement.
How to repair a debonded render:
- Remove the hollow debonded render from the wall- correct preparation of the background surface is essential.
- The surface must provide a good key. It should be clean and sound; an external bonding agent is recommended.
- The patch repair should be of a similar mix proportions to the original render and would typically be a 1:4 or 1:5 (cement: sharp sand volume) mix.
Contact us today here at Greengates Builders Merchants Accrington, Lancashire to get what you need!