Dictionary of Moisture Protection & Restoration

INSTALLATION

Of all factors affecting the performance of a sealant, installation is the most critical. Successful installation depends on several steps including: 1. Joint preparation. 2. Priming when required. 3. Installation of backer rod or backing tape. 4. Mixing, applying, and tooling of sealant. Joint preparation A. Problems: Joints are not

cleaned or are contaminated, incorrect solvents are used and substrates are not dry. B. Solution: Use two rags: one to wet the joint with solvent, the other to wipe the joint.

Using one rag will only smear the contaminants. Remove all mortars, aggregates and foreign matter as the sealant will only pull them away from the substrates when the joint moves. Other contaminants such as sealers, oils, waxes, and curing agents will require removal using mechanical methods such as grinding. Please remember, after a mechanical cleaning, the joints must be recleaned to remove dust and residue left behind by the mechanical cleaning.

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