Making a door jamb requires several key materials and tools. The main requirements are wood boards for the actual jamb, wood glue or nails to join the boards together, a saw to cut the wood boards to size, a drill for creating any necessary holes, wood putty for filling holes and imperfections, sandpaper for smoothing the wood, and paint or stain to finish the jamb. Choosing the right materials and tools upfront will make the installation process go smoothly.
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Types of Door Jambs
There are several different types of door jambs to consider when deciding what to make:
Standard Pre-Hung Door Jamb
A standard pre-hung door jamb comes with the frame and casing already assembled around the door. This is the easiest type of jamb to install since it comes ready to go right into the door opening. For a basic installation, a pre-hung jamb requires minimal materials other than shims and nails or screws to secure it in the opening.
Knock Down Jamb
A knock down jamb comes in pieces with the frame rails, header, stops, and casings all separated. This type requires assembly but allows for more custom sizing to fit the opening. Knock down jambs need wood glue or nails to join the pieces together prior to installing.
Solid Wood Jamb
Custom jambs are made from solid wood cut precisely to the measurements of the door opening. This type provides the most custom and seamless fit. However, solid wood jambs require the most material and expertise to construct from scratch.
Jamb Materials
The main material for making a door jamb frame is the wood boards. There are several wood species commonly used:
Pine
Pine is an affordable and easy to work with softwood. It can be stained or painted and has moderate durability. Pine is a good choice for paint-grade interior jambs.
Oak
Red oak is a popular choice that has good strength and takes stain well. It has an attractive grain pattern. White oak is similar but has a lighter tone. Oak works for both interior and exterior jambs.
Mahogany
Mahogany is a high-end hardwood valued for its rich red-brown color and ability to take detailed carvings. It has excellent decay resistance for exterior use. However, mahogany is more expensive than other woods.
Engineered Wood
Some ready-made jambs utilize engineered wood made from gluing sheets of wood together. This makes the wood more stable against warping or shrinking. Engineered wood is often used for pre-hung jambs.
Jamb Dimensions
Having the right dimensions is crucial when assembling door jamb components. The key measurements needed are:
Door Width
This determines the length of the head jamb and sill. Allow an extra 1-2” on each side for attaching casings.
Door Height
The door’s height determines the length of the side jambs. Make them 1⁄4-1/2” taller than the door.
Jamb Depth
Standard jamb depths are 4-9/16” or 6-9/16”. This is the width of the jamb that will be inset into the wall’s rough opening.
Jamb Thickness
Typical jamb thicknesses are 1-3/8”, 1-3/4″, or 2-1/4″. Thicker jambs provide more stability.
Having these measurements will make it easier to calculate how much material is needed. Make sure to account for the thickness of any casings when taking measurements.
Tools for Constructing Jambs
Certain tools are needed to fabricate custom jambs from scratch:
Miter Saw
A miter saw accurately cuts the ends of jamb boards at 45 degree angles to form clean joints at the corners. A compound miter saw can tilt the blade to also cut any beveled edges.
Table Saw
A table saw equipped with a stacked dado blade allows cutting precision grooves to insert panels of the door. A standard blade makes rip cuts to width.
Router
A router shapes the edge profiles on jamb boards to add decorative details. Common profiles are ogee, chamfer, bead, and roundover.
Drill
A power drill makes holes for inserting fasteners to assemble the jamb or anchor it to the rough opening. A counterbore bit helps recess bolt heads.
Brad Nailer
A brad nailer quickly fastens smaller trim pieces and applies casing around the jamb. 18 gauge nails attach without splitting wood.
Wood Files
Files smooth rough edges and allow fitting joints for a tight seam between boards. A rasp gently shapes curved profiles.
Sandpaper
Sandpaper in varying grits (60, 100, 150) sands down wood surfaces in progressive steps to achieve a smooth finish ready for painting or staining.
How to Assemble Door Jambs
Once you have the needed wood boards and tools, follow these general steps to assemble door jambs:
1. Cut boards to required lengths according to door opening’s measurements.
2. Set blades on table saw to cut grooves for housing door panels (if needed).
3. Use a router to shape edges of boards into desired profiles.
4. Cut ends of jamb boards at 45° angles with miter saw for tight-fitting corners.
5. Drill holes for fasteners to join boards and anchor jamb to studs.
6. Clamp boards together and join with wood glue and nails or screws.
7. File joints smooth. Sand wood surfaces up to 150 grit to prep for finishing.
8. Apply preferred paint, stain, sealer to finish jamb. Apply multiple coats for protection and richness.
9. Install completed jamb into rough opening. Check for plumb and square. Shim as needed.
10. Attach casings around jamb to cover seam between frame and wall.
Following these systematic steps will result in installed jambs with clean lines and details. Employ patience when cutting, joining, and sanding for best end results.
Installing Pre-Hung Door Jambs
For those using ready-made pre-hung jambs rather than building from scratch, the installation process is simplified:
1. Confirm rough opening is properly sized and square. Make any adjustments prior to jamb fitting.
2. Dry fit jamb in opening to check fit. Mark areas for shimming if gap is uneven.
3. Apply sealant to foundation sill and set jamb into opening. Center within rough frame.
4. Use pairs of shims at hinge locations to adjust jamb plumb and square.
5. Fasten jamb to framed opening using long screws through shims into studs.
6. Use shims and nails to secure threshold snugly to subfloor.
7. Install pre-hung door into jamb per manufacturer’s directions. Adjust gaps and hardware function.
8. Complete by installing matching casings around jamb perimeter to cover any gaps at wall surface.
Pre-hung jambs allow faster installation as all materials come pre-cut and assembled. The key steps are proper shimming for plumb and securing firmly into framing members.
How to Install Replacement Jambs in Existing Openings
When retrofitting new jambs into old openings, the process requires extra preparation:
– Remove existing jamb, door, casings completely from opening. Inspect for any damage or rot.
– Repair framing if needed. Verify rough opening dimensions still match new jamb size.
– Chisel out residual old sealant. Scrape surfaces clean. Vacuum debris.
– Fill any holes or cracks in opening framing with patching compound. Sand smooth when dry.
– Seal opening perimeter with acrylic caulk for moisture protection. Let cure before jamb fitting.
– Follow same installation steps for securing new pre-hung or custom jamb in prepared opening.
– Take care not to damage wall surfaces around opening when installing components.
– Patch nail holes and gaps at casings with putty. Sand and finish patching areas.
– Finish by sealing all transitions along new jamb perimeter with paintable caulk for clean look.
The extra preparation is worth it for long-lasting performance from the new door assembly.
Tips for Hanging Doors in New Jambs
Installing doors properly in jambs is just as crucial as framing the jamb accurately:
– Use shims at each hinge location to plumb door in jamb and align margins.
– Make sure hinge locations align between door and jamb. Adjust as needed.
– Follow manufacturer’s directions for hinge types and fastener placement. Do not overtighten.
– Check door operation to open/close without binding before finalizing hinge screws.
– Adjust strike plate on jamb so latch deadbolt align correctly entering plate.
– For exterior doors, apply weatherstripping tape or gaskets around full perimeter to seal gaps.
– Use longer screws on lockset strike plate to reach solid framing behind jamb.
– Lubricate hinge pins periodically to maintain smooth pivot action after install.
Taking the time to hang doors properly will guarantee long service life for the entrance. Doors should operate easily without dragging on jambs or floors when correctly installed.
How to Install Jamb Extensions or Overlays
If existing jambs are damaged or need aesthetic improvement, it is possible to install new overlays over the old surfaces rather than fully removing them:
– Inspect underlying jamb and repair any rot or structural damage first before applying new overlay.
– Remove all old paint or finishes from original jamb surface. Sand to raw clean wood.
– Measure existing jamb thickness and buy new overlay boards in same dimensions for seamless sizing.
– Use construction adhesive to bond overlays to old jambs. Alternately, small finish nails may be used but require filling holes.
– Mitre cut overlay ends at 45 degrees and join at corners. Sand any rough joints smooth.
– Router or plane overlay boards as needed to clear any existing door stop blocks.
– Finish jamb extension same as rest of jamb and wall trim. This disguises the new construction.
– Reinstall door hardware and test operation to ensure proper clearance with new overlay thickness.
Jamb overlays provide a fast facelift without removing the original framing. They can update the appearance without the effort of full jamb replacement.
Conclusion
Installing a proper door jamb provides long-lasting performance for the entrance assembly. Following good techniques for sizing, joining, and fastening the jamb components will result in a smooth operating door. Using quality materials suited for the location, whether interior or exterior, guarantees durability. Patience in measuring twice and cutting once makes the difference in achieving tight seams and gap-free finishes. Whether building from scratch or retrofitting existing openings, understanding sound methods for hanging doors in jambs is a home improvement skill that boosts quality of living spaces for years to come.