Solid fill blockwork requires 28 days cure time before final sealing applications can be applied. However, honing and initial water repellent/primer (WS405) application can be carried out as soon as seven days after laying is complete. Block brick veneers require 14 days cure time before honing can begin, to avoid unsettling mortar joints.
We use hand-held grinders, coupled with industrial vacuums, making the process dry and dustless. We use premium quality diamond abrasives to achieve a quality finish. We do not hone or seal blocks when they are wet or moisture is present.
If you have solid filled masonry walls that form part of your dwelling it is required under the NZ building code that they are treated with a weather-proofing coating. If they are free standing landscape garden walls, there is no requirement for sealing however it can help with preventing deterioration through weathering, and efflorescence; white salts leaching from the surface which may start to occur. We only use the Sto range of clear weatherproofing systems, that meet the NZ building code requirements and come with a substantial warranty that is backed by the manufacturer, and have a proven track record.
It is recommended that re-coat is carried out every seven to ten years, dependant on the environment. Coastal properties exposed to high winds and rain, may require maintenance sooner. Our chosen sealing system; Sto, have a quality assurance maintenance program that logs every project in a database and sends a reminder when inspections are due.
The Sto coating system we use, comes with a manufacturer backed warranty, that ensures peace of mind. The normal warranty period is seven to ten years, dependant on the coating system applied, and project specific details.
To retain the natural fair face, it is imperative that the block layer is made fully aware that the blocks are not going to be honed, plastered or painted, and that they will be clear sealed in their natural state. This way, the block layer will take extra care when pointing and will keep the block faces clean. This avoids the need for any acid washing or light honing before sealing, which may detract from the natural aesthetic. Please contact us for project specific advice.
We have a Sto sealing option which creates a slightly darkened effect with a satin finish. This can be applied on both structural, solid filled walls, veneers, and garden landscape walls. We do not use or recommend the use of any solvent based sealing systems, which often provide a desired wet look, but offer a significantly reduced life span, and often do not meet requirements of the NZ building code.
We strongly recommend sealing concrete block and brick veneers. Although not required by the NZ building code, it’s an investment worthwhile considering to keep the natural aesthetic of your block work looking pristine, and will avoid premature weathering.
In the case of solid filled walls, we are on-site before the joinery is installed to ensure proper waterproofing is extended into the window rebates, at which time we will carry out the honing prior to installation of the joinery. In the case of block brick veneers; we prefer to pre-hone the block ends before they are laid around joinery. We will then return to finish the rest of the area once laid. It is possible to hone veneers in-situ around windows, if absolutely necessary.
Sto Protect: consists of application of WS405 silane water repellent by low pressure spray. Followed by application of Sto Protect waterborne physical coating which is rolled on to block faces and cut into mortar joints with a brush. This system leaves a low sheen finish with a moderate darkening effect. Meets building code for application on structural solid filled block walls requiring weatherproofing to the NZ building code requirements. Can also be used on brick and block veneers, landscape garden walls if desired.
Sto S-Protect SC: Consists of application of WS405 silane water repellent by low pressure spray. Followed by application of SC (Stay Clean) high strength hydrophobic sealer. Creates a super beading effect and is ideal for block brick veneers and landscape walls. This system does not leave a sheen, and will only slightly darken the appearance of the concrete.
There are three main styles of mortar joints; raked, concave and flush. It is important that the block layer is made aware that the walls are to be honed and/or sealed to ensure attention to detail, so that joint finishing is to a high standard. We are happy to discuss directly with your block layer the best way to achieve the look you are after.