Door Threshold / September 14, 2018 / Laure Lacharite.
But what about retrofitting a new entry door system in an older home built with cinderblock masonry walls? You cant 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 Ive 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.
Some manufacturers have now manufactured plastic covers to protect their exact thresholds dimensions and include the covers with the complete door unit. There are other pre-molded protectors available from online suppliers of temporary protection products. There are also a variety of tapes that can be used for threshold protection. Currently the best tape on the market T-X268 is a specialty tape that combines UV chemicals in both the tape and adhesive so it wont break down with ultra violet light. There are additional tapes available for sill protection as well including those made with blue polyvinylchloride.
Tightly wedged shims will allow you to operate the door carefully. Open and close to check the door touching the weather stripping evenly top to bottom for any possible jambs twist. Adjust as necessary even though jambs may not flush with plaster top to bottom. A good carpenter wont assume the original door was installed correctly right? Check the brickmold reveal you should have consistent and even measurements side to side and top to bottom. Its 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 so be patient - you will be rewarded with a satisfying outcome.
When youre satisfied that 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. Drill the strike jamb in the same corresponding locations with the middle drilling positioned between the strike and deadbolt mortises. Countersink jambs holes to flush the masonry screw heads. It may be necessary to remove the 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.