Stone Retaining Walls — Tuck-point to Preserve Them
Even the best-built walls will someday succumb to the powers of Mother Nature and at some point will need some kind of repair. Basically, the repair is a re-setting of few loose stones and the replacement of deteriorated or missing mortar joints.
The first step of the tuck pointing process is to thoroughly pressure wash the wall. Washing with pressure will help to remove dirt and loose material. This not only removes the mould, dirt and soot but the pressurized water will incise the surface of the joints which will support in the bonding of the replacement pointing mortar.
Proper care should be taken not to get too close to the wall. It might take few minutes to calculate out the distance needed to get the best cleaning operation without destroying the wall.
Fill in all mortar joints if you can. Whenever there’s a stone tuck pointing job always try to persuade the customer to completely point out all the mortar joints.
There are basically three reasons for this. The first reason being that most walls have rake joint so it is easy to point out the existing mortar.
The second reason is that the appearance of all the new pointing mortars will be identical since all the joints will be tuck pointed. This inhibits problems when the customer is assuming the new joints to match the old joints perfectly, this is something everyone wants but most are not willing to pay for
The third reason is that you can make use of a grout back to fill in the joints which allow for faster installation time and gives more value for the money spent.
Also use bonding agent which will help in the beginning with water dispersion during the mix but it becomes uncertain on hot days due to the drying of the mortar in the grout bag.
So, good advice would be to keep the mortar loose and regularly clean and dampen your grout bag in order to remove any hard material. This will enable you to apply steady pressure as you grout the joints to a uniform thickness and make the application easier and simpler.
Squeezing the mortar in its place — How to place the tuck pointing mortar can be done in several ways but the grout bag is the most productive way of doing. You have to begin at one end of the wall and start filling all of the wide holes in the wall with new mortar. Just make sure that it is of the same height as the existing mortar joints.
Finishing the tuck pointing of stone retaining walls — After you have grouted an adequate area take a fat tuck pointer of ¾" or bigger, depending on the size of the joint and begin to push the mortar into the joint between the stones. This binds the joint and closes off any voids that might have been missed during the grouting process.
With all masonry repairs, the process is not too difficult but if you want your stone retaining walls to be presentable and to look nice, you have to pay attention to the details.
About the Company
DMI Drilling Construction has been providing retaining wall services to clients across Washington State since 1991. The company specializes in a variety of techniques, including the creation of caissons, soldier pile wall, piers and soil nails, that are meant to ensure stable foundations and safer working conditions.