A minimum of four Corefix Connect fixings per shelf is recommended, with additional fixings used for longer or heavier shelves. Four fixings give a Safe Working Load of 100kg in solid brick and blockwork, which is more than sufficient for most domestic floating shelf applications. Spreading the fixings evenly across the bracket positions distributes the load across the masonry and reduces the stress at any single point. If the shelf is particularly long or is intended to carry heavy items like books or equipment, using more than the minimum four fixings is a sensible precaution.
How to securely fix a floating shelf to a dot and dab plasterboard over block
In brief: Floating shelves look clean and simple, but on a dot and dab wall they are one of the more common causes of a fixing failure, because the weight of a loaded shelf pulls both down and outward from the wall simultaneously. Standard fixings either grip only the plasterboard, which will eventually give way under the load, or crush the plasterboard inward as the screw is tightened. A specialist dot and dab fixing like Corefix Connect anchors the shelf brackets into the solid blockwork behind the plasterboard, giving the shelf a secure and stable base regardless of the weight placed on it. Four fixings per shelf is the recommended minimum.
First of all: What is Dot and Dab?
Dot and Dab plasterboard dry lining has become very popular in recent times as it can be a very quick and easy way to finish a wall without needing any specialist trades. Over 80% of the UK’s new build houses use this method as it reduces costs and increases speed of completion.
Plasterboard can be attached by three methods, either, mechanically (with screws), chemically with plasterboard adhesive or by using plasterboard fixing foam. Fixing using plasterboard adhesive is known as dot & dab or direct bonding and has several advantages over screws as it can be bonded directly to bare bricks which gives considerable speed advantages.
How can I fix stuff to Dot and Dab?
One of the biggest issues with using dot and dab is that it can be very difficult to fix to because plasterboard cannot support substantial weight. The solution is to use a specialist dot and dab plasterboard fixing, such as Metex Corefix.
Metex Corefix is made up of 3 parts: an expanding wall plug, heavy-duty steel core and screw. The set of components work together to bridge the plasterboard and the cavity, transferring the load of the fixture from the plasterboard to the blockwork behind.
This provides an incredible, and independently tested, safe working load of 100kg in Masonry block work on 4 fixings, and 73kg in Lightweight Thermalite blockwork. By supporting the screw that will hold the load using the steel core it is possible to safely and securely fix heavy floating shelves to dot and dab wall.
How do I install a shelf with Corefix Connect?
Easily! Just follow these steps:
- Mark the required location of shelving bracket holes. Generally a minimum of four Corefix Connect dot & dab wall fixings would be used per shelf. Drill hole to required depth using a 10mm masonry or SDS drill bit.
- Ensure all debris and dust has been removed from the hole. Gently tap the Corefix plug into place until the flange contacts the wall surface.
- Tap the metal core into place until it is flush with the Corefix plug flange.
- Offer the shelf bracket up to the wall and ensure bracket is totally secure and that screws are ‘tightened up’ in all fixing locations. If shelf is to be used to support heavy loads, ensure shelf bracket is secured to underside of shelf to avoid this slipping forward.
To see this in practice, check out what @UltimateHandyman thought of Corefix Connect when he came to fixing a floating shelf to dot and dab plasterboard over brick!
It’s no secret, we love them! This age old problem that has plagued us (and many others) for many years has now been solved thanks to Corefix Connect. Corefix Connect is a relatively simple solution to a very big problem and we think these fixings deserve a place in everyone’s toolbox.
For more information on where to purchase the Corefix range, click here!
Frequently Asked Questions
Can you fit a floating shelf to a dot and dab wall?
Yes, but it requires the right fixings. Floating shelves are one of the more demanding applications on a dot and dab wall because the weight of the shelf and whatever is placed on it creates both a downward shear force and an outward tensile force on the fixings simultaneously. Standard wall plugs and plasterboard fixings are not reliable for this combination of forces on a dot and dab wall. A specialist fixing that anchors into the masonry behind the plasterboard, like Corefix Connect, transfers both forces to the solid blockwork and gives the shelf brackets a stable, secure base regardless of what is placed on the shelf.
Why do standard fixings fail under the weight of a loaded floating shelf on a dot and dab wall?
A loaded floating shelf places two types of force on the fixings at once. The weight of the shelf and its contents pushes straight down, which is the shear force. But because the shelf projects out from the wall, the bracket also pulls the top fixings outward and pushes the bottom fixings inward, which is the tensile force. On a dot and dab wall, standard fixings have nothing solid behind the plasterboard to resist either of these forces reliably. The plasterboard around the fixings gradually crumbles under the combined load, the fixings loosen, and the shelf becomes unstable before eventually failing.
How is dot and dab plasterboard attached to the wall and why does this affect fixings?
In dot and dab construction, plasterboard is fixed to the face of solid masonry using blobs of adhesive applied in a pattern across the blockwork. The adhesive dabs space the board away from the wall, leaving a gap of typically 10 to 25mm between the back of the plasterboard and the face of the masonry. This method is fast, cost-effective, and produces a smooth surface for decorating, but the gap it creates means there is no solid backing directly behind the plasterboard. Standard fixings either grip only the board or crush it inward when tightened, neither of which is suitable for a loaded floating shelf.
Does the bracket need to be secured to the underside of a floating shelf as well as the wall?
Yes, for shelves carrying significant weight. If the shelf bracket is only fixed to the wall and not secured to the underside of the shelf itself, the shelf can slide forward off the bracket as weight is added, particularly if the load is uneven or positioned toward the front edge. Securing the bracket to the underside of the shelf with appropriate screws locks the shelf in place and ensures the full weight is transferred through the bracket to the wall fixings rather than relying on friction or gravity to keep the shelf seated.
What is the easiest way to install Corefix Connect fixings for a floating shelf?
Mark the required bracket hole positions on the wall and check for pipes and cables with a detector before drilling. Use a 10mm masonry drill bit to drill each hole to a minimum depth of 100mm, clearing dust from each hole before fitting the fixing. Tap the Corefix Connect plug into each hole until the flange sits flush against the plasterboard, then tap the steel core home until it is level with the plug face. Offer the shelf bracket up to the wall, align it with the fixing positions, and screw into place using the supplied screws, tightening each one fully before moving to the next. Once the brackets are secure, attach the shelf and check it is level before loading it.