1) General Requirements for Repointing a) The surface area of the wall is approximately 2,000 square feet. It is estimated that 40% to 50% of the mortar needs to be removed and replaced. b) Whenever mortar has lost 1/4 inch of its original depth, it's time to get out the chisel and go to work. Thoroughly rake out and clean joints to a depth twice the width of the joint. c) Do not chip, cut or remove the brick's fire-skin, which will accelerate decay. d) Repoint only when temperatures remain between 40 and 90 degrees Fahrenheit, even at night. Cold makes mortar brittle, while heat dries it out and prevents hardening. e) Keep fresh lime mortar damp for at least 3 days so it can harden before it dries. Taping plastic sheets over repointed areas will slow evaporation. After the sheets are removed, hose the wall periodically during dry spells to speed hardening. f) All bidders need to supply to the school’s representative what type of staging, lifts, etc. that you plan on bringing to the site and use. g) Make sure the site when you leave looks the same as when you first started. h) Cover the ground for the slag that falls from the process so as not to ruin any greenery. i) Wash the wall after the project is completed to clean up any over slag that might have infiltrated the brick face by mistake. Also let the same representative know what type if any cleaner you plan on using to fulfill this process. Being a school, any type of course agents must be diluted to a safe level. j) If and when grinding is done, cleaning the dust off of other areas not in the scope of work will be necessary. k) If anything is noticed that is outside of your scope, immediately bring it to the representatives' attention without proceeding unless released to do so. 2) General Requirements for Applying Water Repellants a) The contractor will use a Siloxane based water repellant to seal the surface of the brick once the repointing is completed. b) The contractor can use either of the following products or an equivalent. i) Blok – Lok Siloxane with MICRO – LOK, by Rain Guard Pro. ii) Sure Klean Weather Seal iii) Product data sheets are attached to this Request for Proposals for reference. iv) If an alternate product is used, the product specifications must be submitted to the Owner and the Owners Consultant for approval. c) Choosing the correct water repellant is the most important aspect of finishing this project. If a pre-mix is chosen, it must be for the use on brick, and water-based. If the product is a Concentrate, then it needs to be mixed properly. Either way the mixture rate for brick is 14 parts of water to 1 part of product for concentrates. Pre-mixed should be marked "for brick." d) When proper product is on site, then the application procedure is; i) clean dry brick & mortar ii) temperature is 40 degrees and rising for a minimum with no overnight freezing in the forecast, iii) no rain in the forecast for the next 24 hours. e) When applying, a low-pressure sprayer is recommended for optimal outcome. Never use a painter’s sprayer that applies latex paint because it will ionize the liquid and saturation will not be optimal. f) When spraying, start from the bottom, working your way up to the top. Saturate the surfaces until repellant is rejected. i) Never start at the top working down, the repellant will never saturate properly. g) Protect all surfaces not to be sprayed with plastic or other protective products. This includes glass, aluminum, steel, etc. h) When starting from the bottom, saturate surfaces enough to allow an 8-inch run before moving up to repeat the process.
