Parging: An Explainer

A masonry technique that hides imperfections in walls or structures or covers a concrete block wall or structure, parging is similar to stucco in what it does, but the mixing the mortar, as well as applying it, in the parging process is a job for masonry experts. At Chimney Saver Solutions, our skilled and experienced masons pride themselves on their Portland cement and limestone-based mortar restorations. Since parging is not as well-known as stucco, we would like to explain it better to you and to tell you the 10 steps to a successful parging job.

The 10 Steps

1. To ensure the parging mortar will stick to the surface, we remove tar, paint, glue, and/or other blemishes with a hand grinder.
2. To give the parging mortar something to stick to, we cut very small vertical cracks along the surface, spacing them about a foot apart from the other.
3. It is now cleaning time. We sweep all the dust and debris away from the surface, taking extra care when we are doing the foundation of a home. We be sure to brush out the underside of the home’s siding where it meets the foundation because that area is a prime location for spiders spinning webs and insects building nests.
4. Laying down a drop cloth on the floor or ground, we always protect the surfaces underneath before beginning our parging work.
5. The first tricky part to parging is mixing the mortar correctly with the right amount of the right ingredients. The dry portions of the mortar are Portland cement, sand, and other aggregates. Adding just the right amount of sand is important because the parging mortar needs the sand to make it sticky. If you do not add enough sand, the mortar will simply slide down the surface and not stick; too much sand makes the mortar too grainy. Water is added to the dry mix, and we have parging mortar. Since this mortar dries very quickly, we only mix enough to use in 20 minutes.
6. We then test the mixed parging mortar with a trowel to see if the mix has been done properly. If so, it should resemble mud with a plastic consistency.
7. Before applying the parging mortar, we wet down a two-foot by two-foot area of the surface, and we know, for the best parging finished appearance, to start wetting the surface at the bottom and to work our way upwards.
8. Using a pointing trowel, we then begin to apply the parging mortar, spreading it evenly over the surface in a half-inch thick coat and overlapping the edges. During this step, we occasionally mist the surface with water as this helps the mortar mix to stick to the surface.
9. Continuing to mix and apply the parging mortar, we pause briefly after covering about eight square feet to mist that section of the parged surface again with water. Then we use the trowel to smooth over the surface to create a polished, clean look.
10. Once the job is complete, we will recommend waiting at least 24 hours of drying time before painting the parged surface.

If you have any more questions about parging and how it can improve the appearance of your home, contact us at Chimney Saver Solutions. Our masons are happy to tell you more about this masonry restoration procedure.