DAVID TAYLOR REMODELING
Installation of an Entry Door-Direct Fasten to Masonry
I’ve always enjoyed installing residential entry doors. There’s something about thinking and working in three planes that appeals to me. Making customers happy and feeling comfortable in their home environment makes me happy, too. Nothing can compare to the satisfaction of knowing a job has been well done, seeing and feeling a beautiful and properly installed door operate smoothly. In modern homebuilding techniques, most housing built here in the Salt Lake City area after the mid-1960’s is 2x4 or 2x6 wood stick frame construction with an exterior veneer of brick, stucco, or some type of lap siding. Prior to that time, many, if not most, homes around here were built using four inch wide cinderblock (4”x8”x16”) masonry walls with a brick exterior veneer.
Thermal efficiency properties of new door systems have improved greatly over what was available forty or fifty years ago. New jambs allow for air-tight vinyl weather stripping and adjustable thresholds with vinyl door bottom sweeps. Low maintenance fiberglass or metal doors are sandwiched with foam insulation. And doors with windows come with thermal glass. Installing a new door in an existing older home has become a highly desired remodeling upgrade.
These days, installing a pre-hung entry door system (including jambs) to new wood stick frame construction is generally pretty straight forward; you can just nail, or preferably, screw through the jambs to the framing studs behind. If adjustments are necessary, just back out the screw, re-align the jamb using builder’s shims, and try again.
But what about retrofitting a new entry door system in an older home built with cinderblock masonry walls? You can’t use the same technique of just nailing through the jambs, the masonry will just deflect and bend a regular framing nail. Cut nails might possibly work, but the chances for jambs alignment adjustments are slim to zero, while the chances of masonry cracks or half-moon hammer head marks in the jambs are almost a given. Masonry screws need to be started in pre-drilled cinderblock holes, which can be drilled through the jamb, but I’ve never been satisfied with their holding power alone, where the cinderblock is prone to crumble around the holes while adjusting screws and snugging shims tight. Experience has taught me to always insert plastic expansion sleeves in the cinderblock to properly fasten masonry screws.
I believe installation of an entry door direct fasten to masonry is the height of challenge for an entry door, where skills and patience for a carpenter are truly tested. You really only have one chance to get it right - screw hole mistakes in the cinderblock don’t allow for incremental jambs adjustments. Here is where carpentry meets art, you must think and be creative. So, the satisfaction of a properly installed door in this case becomes, at least for me, a real thrill.
On the initial site visit to measure up the door, you’re going to tap on the walls to see if they are drywall or plaster covered cinderblock. Of course, you’re going to check the interior walls for plumb. Also, check the concrete threshold step for level. Carpenters never assume anything, right? Measurement of the exterior brick opening overall height from concrete threshold to brick lintel will be noted. Any further uncertainty about whether a house was built with masonry walls can be at least partly resolved by measuring the exterior brick opening overall width. A width measurement slightly off by about one-half inch from the nominal brick opening is a sure tip-off that you’re going to be facing the direct fasten to masonry challenge. Adjust your installation estimate accordingly for some extra labor.
I’ve learned by the hard way of experience that it’s necessary to remove old existing jambs carefully. If directly fastened to masonry with cut nails, roughly removing jambs may break out the cinderblock unless the jambs are cut into short, manageable lengths.
An out of level concrete threshold can be ground flat by a concrete cutting subcontractor, or the door threshold can be adjusted by unscrewing and repositioning in the jamb by the amount out of level. An adjustable threshold also helps here.
Any attached brickmold and casing must be removed from the jambs to make installation easier with shimming. Also, brickmold will probably have to be ripped in width to fit the overall brick opening width and height.
With the rough opening clean and prepped for the new door and jamb, move the system into place as one with door hung on hinges. Temporarily shim the side jambs tight at top and bottom ends in the rough opening. Temporary shims at the bottom hinge will help straighten door sag. The top hinge will sag, just be aware that you will compensate for it later with shims and a screw to snug it when the door is installed permanently. Further use of a level isn’t necessary, just align the hinge side jambs flush with the interior sheetrock or plaster and shift shims to square the door in the jambs with even spacing reveal. Tightly wedged shims will allow you to operate the door carefully. Open and close to check the door knob side stile touching the weather stripping evenly top to bottom for any possible jambs twist. Adjust both side jambs as necessary, even though jambs may not flush with plaster top to bottom. A good carpenter won’t assume the original door was installed correctly, right? The new door and/or jambs may have slight bows. Check the brickmold reveal, you should have consistent and even measurements side to side and top to bottom. It’s unusual to have brick out of plumb to any great extent. Adjust shims again as necessary. Index the jambs in the rough opening and the shims to jambs with pencil for reference when installing the system permanently.
Remember, you only have one chance to get this installation right, the cinderblock is unforgiving of drilling several holes in close proximity. So be patient – you will be rewarded with a satisfying outcome. When you have the door system is in the correct position, drill through the thickest part of the hinge jamb with a regular drill at the hinges areas, and then further drill into the cinderblock with a hammer drill and properly sized bit. Drill the strike jamb in the same corresponding locations, with the middle drilling positioned between strike and deadbolt mortises. Countersink jambs holes to flush the masonry screw heads. It may be necessary to remove a heavy wood door from the hinges for this step, just remember to check the indexed jambs alignment to be sure nothing has moved.
Remove shims and then remove door system from the rough opening. This must be done to install the plastic expansion sleeves into the holes drilled into the cinderblock. Then re-assemble door system and re-shim into the indexed positions in the rough opening. At last, now fasten jambs to the cinderblock with the masonry screws, using shims at each screw location. Fine tune screw adjustments by wedging the shims to get the reveals around the door even. Adjust top and bottom jamb end shims as necessary. Open and close door to check knob stile touching the weather stripping evenly top to bottom for any possible jambs twist. Some slight remaining jambs twist can be adjusted by persuading the jambs with a block and hammer. Be careful. Now nail the shims permanently in position with a pneumatic nail gun shooting squarely into the cinderblock. Don’t worry, the nails should sink into the cinderblock as long as they are the proper length and gun is held squarely and firmly. When in doubt, nail into mortar joints. Don’t nail into the very hard brick. I try to hide any nailing behind the weather stripping whenever possible. Finally, protruding shim ends may be trimmed off with a dove-tail saw.
Squirt foam insulation between cinderblock and back side of jambs. The foam can help glue the jambs into place. Then all that’s left to do is apply the frosting - trim of brickmold, casing, and a shiny brass or brushed nickel doorknob. Stand back and feel satisfied knowing you’ve accomplished something out of the ordinary, and made the customer happy and secure.