Textured masonry sealants from DAP, Sashco and Quikrete name mortar and stucco cracks. Check each one’s widest joint: they run from 3/8 inch to 3 inches.
Masonry sealants, by joint width
| Product | For | Widest joint | Paint |
|---|---|---|---|
| DAP Textured Mortar | Mortar, masonry, stucco, brick, stone | 3 inches wide by 1/2 inch deep | After 2 hours |
| Sashco Mor-Flexx | Mortar, stucco, stone, faux stone | 3 inches | After 4 hours, water-based |
| DAP Textured Concrete | Concrete, masonry, brick, cinder block | 1/2 inch wide by 1/2 inch deep | After 2 hours |
| Quikrete Stucco Repair | Stucco cracks | Cracks up to 1/2 inch; 3/8 inch per coat | Wait 24 hours, latex only |
| Quikrete Mortar Repair | Mortar joints in masonry walls | Made for 3/8 inch joints | After 24 hours, latex only |
From each product’s data sheet. Deeper than 1/2 inch, DAP and Sashco say to use backer rod.
Why a flexible sealant, not mortar
Sashco’s reasoning: a crack is there because that spot is under stress, so new mortar in it will likely pop out. Sashco rates Mor-Flexx for 12.5% joint movement; it can go on damp areas but wants 24 to 48 hours before direct rain.
Limits to know
- Quikrete says its Mortar and Stucco Repair aren’t for control or expansion joints or structural repairs, and not to apply them if rain is due within 12 hours.
- Gorilla rules out brick, masonry and cementitious materials for its 100% Silicone Kitchen & Bath and Window & Door sealants.
- Sashco says Mor-Flexx won’t stick to silicone, so old silicone has to come out. Loctite says to remove old brick caulk mechanically before resealing.
Sealing somewhere else?
Caulk finder