Quartz countertops can provide an attractive and durable surface for kitchens and baths. However, proper cabinet construction is critical prior to countertop installation. Press board cupboards may not offer adequate support for heavyweight quartz counters. Here is an in-depth look at whether quartz countertops can be installed on press board cupboards.
What is Press Board?
Press board, also known as particle board or chipboard, is an engineered wood product made from wood chips, sawmill shavings, or even sawdust. The material is combined with resin binders and pressed into sheets under high temperature and pressure.
Press board is a popular choice for cabinet construction because it is inexpensive and easy to work with using basic woodworking tools. However, press board is less dense and structurally rigid than plywood or solid wood. It lacks the strength to properly support heavy countertops without reinforcement.
Challenges of Using Press Board Cupboards for Quartz
Quartz countertops typically weigh between 15-20 pounds per square foot, making them a heavy material compared to laminate or granite. Installing quartz on press board cupboards comes with a few difficulties:
Insufficient Support – The lower density of press board means it cannot provide enough structural support by itself under the weight of quartz. This can lead to sagging counters or collapsed cabinets over time.
Vulnerable to Moisture – Press board absorbs water easily and swells. Exposure to moisture from spills or leaks can compromise the integrity of the cabinets. Quartz counters are impervious to water.
Prone to Fastener Pull-Out – The resins binding press board together tend to soften under sustained heavy loads. This reduces the holding strength of screws, causing fasteners to loosen or pull out as the countertop settles.
Susceptible to Damage – Press board dents and gouges more readily than wood or plywood. Care must be taken not to damage cupboards when installing and living with quartz countertops.
Best Practices for Installation on Press Board
Installing quartz on press board cupboards can work only if the proper steps are taken to reinforce and support the cabinets:
- Add Support Braces – Affix vertical braces to upper cabinets and horizontal braces to base cabinets. Use 3/4″ plywood for maximum strength.
- Install Thicker Backing Board – Remove press board tops and replace with 3/4″ plywood prior to countertop installation.
- Use Longer Fasteners – Quartz installers must use screws that extend rearward into the cabinet wall framing, not just the press board.
- Seal Exposed Edges – Apply water-resistant varnish or laminate to the bottom edges of press board to avoid moisture damage.
- Handle Carefully – Take precautions not to crack or impact the countertops. Use soft cushions when placing items on quartz over press board.
Should You Avoid Press Board?
While it is possible to install quartz on properly reinforced press board cupboards, it introduces many risks that can be avoided. Using plywood or solid wood cabinet boxes is highly recommended for long-lasting strength under a heavy quartz countertop.
Press board cupboards should only be considered if the absolute lowest project cost outweighs concerns over structural integrity and durability. For most homeowners, investing a bit more in proper cabinetry for quartz counters is worthwhile. Consult with countertop installers to explore options before committing to press board.
FAQ About Quartz Countertops on Press Board
Can you put quartz straight on top of press board?
It is not advisable to install quartz directly on top of unmodified press board. The press board must be reinforced with vertical and horizontal bracing and have the top replaced with plywood before installing the quartz.
How thick should plywood be under quartz?
Plywood added on top of press board cabinets should be at least 3/4″ thick for suitable strength under quartz counters. Thicker 1″ plywood offers even greater rigidity.
Do you need extra support for quartz countertops?
Some additional bracing and support is recommended during quartz installations to prevent long-term cabinet damage. Exact requirements depends on cabinet construction but extra braces are always a good idea.
Can press board cabinets hold granite?
Granite is also heavy, so press board cupboards alone do not offer adequate support. As with quartz, press board must be reinforced and topped with plywood before granite can be installed.
Is it worth reinforcing press board cabinets?
In some cases it can be worth the effort and expense to reinforce press board to support heavyweight counters. This is most practical for recently purchased cabinets. Older or lower-end cabinets may not merit investment.
Installing heavy quartz counters on unmodified press board cupboards is risky and can lead to cabinet damage or countertop failure down the road. With proper reinforcement using braces and plywood, quartz can potentially be added to press board successfully. However, using higher quality cabinetry is highly advised for the best results under quartz countertops. Consulting professionals is recommended when considering quartz installation on anything less than rigid cabinet boxes.