Masonry chimney repairs can be difficult to do yourself, especially if they are widespread over a lot of the area of the chimney. Extensive damage often requires the chimney to be partially or completely rebuilt, but sometimes a quality do-it-yourself repair will suffice. A good chimney repair takes a lot of time and effort. As with any aspect of home improvement, cutting corners on creates more work and causes more money to need to be spent than having done it the right way the first time. Doing it right, the first time, is a motto that all of my service men operate by and is a good starting place for do-it-yourselfers.
Take for example the tuckpointing repair, which constitutes repairing crumbling or missing mortar joints on the chimney. This is a difficult repair for homeowners who are not experienced in masonry repairs because of the various tools it requires as well as the finishing the look of the mortar so that it looks professional and not sloppy. One of the more difficult aspects is cleaning out the mortar from in between the bricks in the first place. It is imperative to be careful when using the chisel and hammer because trying to move too quickly will result in damaging the brick.
Another tricky repair is actually removing and replacing a damaged brick or a few damaged brick from the chimney. This repair can be difficult mainly due to the fact that the actual removal of brick takes a certain level of caution in order to not cause damage to surrounding brick. If you have only a handful of damaged brick on the chimney and the surrounding brick are generally in good condition, you can actually cut out and replace the offending brick. This requires careful cutting of of the mortar and then cleaning the mortar out of the joints to install new brick.
Cracks in brick are less difficult to repair because no cutting of the brick involved, only careful sealing and water proofing. Cracks in your brick can happen for any number of reasons from a shifting foundation to water damage, but carefully sealing cracks and then water proofing the entire affected area is the only way to prevent similar damage from occurring again. If you believe your brick is cracking due to shifting foundation, you will need to bring in a professional to decide why the problem is occurring. If your brick is cracking due to water damage, then this is certainly a DIY repair. Use a silicon seal to seal the cracks from water penetration and then a water repellent over the entire area.
I recommend using a water repellent after any repair, whether you are cutting out and replacing brick, tuckpointing mortar joints, or sealing cracks in the brick. Since this damage occurred in the first place and most of the damage I’ve discussed is caused, generally in some part, by water, applying a deep penetrating water repellent over the entire area is a wise investment because it will protect your repair and the area from further damage.