How hard is it to install a slab door?

Installing a slab door can seem like a daunting task for a homeowner without much DIY experience. Slab doors, sometimes called flush doors, have a smooth flat surface with no panels orglass. They provide a very clean, modern look for interiors. While installing a pre-hung door with jambs is relatively straightforward, installing a slab door from scratch involves more work as you have to build the entire frame to fit the door into the opening. However, with the right planning and tools, even novice DIYers can successfully install a slab door in their home. Here we will walk through the entire process step-by-step.

What You Need

Before starting your slab door installation project, you need to make sure you have all the necessary materials and tools on hand:

• Slab door – Pre-finished or unfinished, sized to fit your door opening
• Jamb material – Pre-primed pine boards or MDF long enough to frame the door opening
• Casing material – For trimming out the jambs after installation
• Shims – Thin wooden wedges to level and plumb the jambs
• Finish nails – To secure the jambs and casing
• Wood glue
• Caulk
• Level
• Tape measure
• Pencil
• Drill/screwdriver
• Saw – Handheld or circular for cutting boards and trimming door
• Planer – For smoothing cut edges
• Hammer
• Utility knife
• Sandpaper

Having all these supplies ready before starting work will make the installation process go faster and smoother. Safety equipment like gloves, eye protection and a dust mask are also recommended.

Preparing the Door Opening

The first step is ensuring you have a proper door opening ready to receive the new slab door and jamb framing. Start by removing any existing door, frame or trim around the opening. The opening should be plumb and square at the dimensions needed for your door size. Use a level and tape measure to check for any irregularities that need correction. The floor under the opening should also be level.

Fill in any gaps around the rough opening with wood shims. Make sure the shims are secured firmly in place but do not over-tighten. Test fit the new door in the opening. It should fit flush all the way around with consistent spacing. Make any necessary adjustments to the shims until the door fits properly.

Cutting the Jambs

With the opening ready, now you can cut boards to size to create the door jambs. Measure the width at the top, middle and bottom of the opening. Cut two boards to the exact height of the opening. Then cut two boards to the width for the sides.

Transfer the measurements to your jamb material carefully and cut with your saw. For clean cut edges, you can use a circular saw, miter saw or a straight cutting hand saw. Sand down any rough edges after cutting. It is important that the boards fit the opening exactly to create a tight seal for the slab door installation.

Assembling the Jambs

Assemble the cut boards into a rectangular frame to fit into the rough opening. Apply wood glue on the ends. Then attach the head jamb (top board) to each side jamb using finish nails. Use scrap wood spacers inside the frame as needed to hold the pieces at the proper width while nailing.

Double check that the frame is perfectly square by measuring the diagonals – they should be equal. Once the frame is squared, nail through the side jambs into the head jamb to reinforce the joints even further.

Installing the Jambs

With the jamb frame fully assembled, you can now install it into the door opening. Run a continuous bead of caulk along the inside edges of the rough opening. Then place the jamb frame into the opening, pressing firmly into the caulk to seal it.

Use shims spaced along each side to adjust the jambs so they are perfectly plumb and square in the opening. Check frequently with a level as you shim. The gaps around the jambs should be consistent. Secure the assembled jambs in place by driving finish nails through the sides into the rough framing. Place shims near each nail and only drive nails snug enough to hold the jambs, being careful not to distort the frame out of square.

Hanging the Slab Door

Before hanging the door, check that the spacing along the jambs is even. Chisel out any areas that are too tight. It is also important to seal the door jambs and slab door edges with primer or sealer to protect from moisture. Once ready, position the slab door in the opened jamb frame.

Most slab doors have pre-drilled holes for the hinges. Line these up with pilot holes you drill in the door jamb. Use a drill/driver to insert the screw eyes of the hinges into the jamb boards. Test the door for proper operation after installing each hinge.

Trimming Out the Jambs

With the door hung in the new jambs, you can complete the installation by trimming out the interior side with casing boards. Cut casing boards mitered at a 45 degree angle to overlap the rough edges of the jambs. Install the trim boards with finish nails, being sure to countersink the nails with a nail set.Aim for a tight fit between the casing boards with no visible gaps.

Finally, caulk along the interior seam of the casing boards and jambs for a finished look. Once dry, the caulk will create a smooth painted surface.

Finishing the Door

For a professional look, fill any nail holes, sand smooth and apply wood putty if needed. An unfinished slab door will need to be painted or stained to match the rest of the interior doors. Allow the finish coats to fully dry as directed by the product.

You now can install the lockset and doorstop hardware. Your custom slab door should now operate smoothly on its new jambs. Installing your own slab door is an advanced DIY project, but following these key steps carefully will lead to success.

Conclusion

Installing a slab door requires more skill and effort than a pre-hung door, but it allows you to customize the door and jambs to your exact specifications. While challenging for beginners, installing a slab door is completely feasible for motivated DIYers willing to take the extra time to follow each step closely. The keys are taking accurate measurements, assembling the jamb frame precisely, and allowing sufficient drying time for finishes. Patience and attention to detail will be rewarded with a beautiful new slab door perfect for your home. With the right planning and preparation, this is a DIY project well within reach and a great way to upgrade interior doors affordably.

Tips for installing slab doors

Here are some additional tips to help ensure success when installing slab doors:

• Use Premier grade wood or MDF for smooth, defect-free jamb boards.
• Allow 1/8″ spacing around the door for expansion.
• Mark hinge locations on the door and jambs precisely.
• Predrill holes before inserting screws to prevent splitting wood.
• Use non-expanding foam insulation to seal any exterior doors.
• Consider adding repel strips to prevent air leaks around the jambs.
• Set nails and fill holes with putty for an ultra-smooth finish.
• Prime all sides of jamb boards before installation.
• Wait 7 days before painting or refinishing a new slab door.

Taking the time to do careful prep work and following best practices will lead to a successful and long-lasting slab door installation. With patience and persistence, even DIY beginners can tackle this project. The end result will update the look of any room.

Cost of hiring a professional

While a DIY slab door installation can save money for handy homeowners, hiring a professional carpenter to do the job is a good option if you are unsure about taking on the work yourself. In most cases, expect to pay $500 to $900 to have a standard sized interior slab door installed professionally. Here is a breakdown of typical pricing:

Project	Professional Cost
Basic slab door installation (labor only)	$500 – $700
Pre-finished white slab door (30″ to 36″ standard size)	$150 – $300
Wood jamb materials	$50 – $100
Door lockset hardware	$50 – $100
Total professional install cost	$750 – $1200

This covers removal of old door, installing jambs, hanging and adjusting the slab door, hardware, and trimming out both sides. Additional charges may apply for non-standard sizes or custom finishes. Hiring a pro ensures expertise you may lack doing it yourself. But for large savings, a DIY install is very feasible if you have the skills.

FAQs about installing slab doors

Many homeowners have additional questions when taking on the project of installing slab doors. Here are answers to some of the most frequently asked questions:

What tools do I need to install a slab door?

The basic toolkit includes a tape measure, level, drill, hammer, saw, plane, shims, nailset, caulk gun, utility knife, and sandpaper. You may also need a circular saw, miter saw or table saw for cutting boards accurately. Safety gear like gloves and eye protection are also a must.

How thick should jambs be for an interior door?

For most interior doors, 1-3/8 inches to 1-3/4 inches is the typical jamb thickness. Thicker jambs provide more strength and stability.

What size gap should be around a slab door?

Leave a consistent 1/8 inch gap around all sides of the door to allow room for expansion and operation. Proper spacing is key for correct clearance.

Should I insulate between slab door jambs?

For exterior doors, use minimal expansion foam between jambs and framing to seal and insulate without bowing the jambs. Interior doors do not need insulation.

How much does it cost to install a pre-hung door vs. slab door?

Pre-hung doors cost $100-$300 on average with installation around $150-$500. Slab doors run $50-$200 plus $500-$900 for full jamb installation.

What is the standard slab door size?

The most common interior door size is 30-36 x 80 inches (762-914 x 2032 mm). Exterior doors are typically larger at 36 x 80 inches or more. Sizes can vary by home.

Can I install the lockset and hinges myself?

Yes, most slab door locksets use simple drill-in installation. Hinge screws are also easy to drive into the jambs and door. Follow the manufacturer instructions.

Conclusion

Installing slab doors provides an esthetic upgrade over traditional panel doors, with clean lines fitting modern homes. While challenging for DIYers, the project becomes approachable by following key steps: preparing the opening, building square jambs, hanging the door true, trimming out cleanly, and sealing properly. With patience and care, homeowners can execute professional looking results and save on installation costs. The improvement after replacing old doors with fresh new slab doors is immediately apparent. Just be sure to budget ample time and stick to best practices throughout the process.