In an historic city, it is not surprising that the brick sidewalks in the city begin to look a bit worn and stained. Yet, a little routine maintenance (Yes, it’s a bad word in city government) and an occasional cleaning will ensure it always looks as good as new. Some cheap sweat of the brow can often give your property a 15 to 20% boost in property value by making the brick sidewalk look great in front of your home. For the rest of you in the historic district who don’t have brick sidewalks, get brick – it’ll boost the look of your home, increase your property value and help the city look better and safer too!
In the meantime, rather than standing idly by waiting for the local city work crews to clean up and make your sidewalk new again. (Not everyone can have their sidewalks done like the recent work on High Street near State which looks so awesome.) You will probably be waiting for a very long time. Besides, after I’ve seen the shoddy blacktop and some rather suspect “repairs” in the city, it might be wiser to make your sidewalk look great on your own.
Although Brick is durable and can last for generations, gentle cleaning is still the best way to keep it looking fresh.
First thing to do is get a push broom specifically designed for outdoor surfaces. Steady and consistent sweeping whenever needed to get rid of dust and debris can go along way to improving the look.
Second, a simple hosing can often remove substances that stain. It should be one of the first things done as spring arrives. Have you seen bricks around the city with a white caking substance on them? That is called efflorescence. It is often the result of using deicers such as salt on the historic brick. The salt draws out the moisture from the old bricks which are very porous anyway and the result is a heavy deposit of impurities staining the brick surface. Believe it or not, it can be removed. Hosing goes a long way toward starting the process.
Third, be careful to start off with gentle cleaning methods. Brick, even the historic Stiles & Hart bricks can be damaged by metal brushes and it will encourage more staining. Use natural or plastic bristles on your brushes. When using cleaning substances, start with gentle cleaners and work your way up to harsher chemicals. Because of the porous surface, be sure to saturate with any cleaner or the affect will be disappointing. Avoid power washing even on brick. If you don’t, you may have a crumbled mess on your hands. Don’t try to save yourself in the future by putting sealers on the brick, it’ll just trap moisture in the bricks and you’ll again have in the near future a crumbled mess.
There are two facts about historic bricks. First fact, they were fired at lower temperatures than modern bricks and therefore, pre-20th century bricks were relatively soft. The second fact, they were often fired in coal-fueled beehive kilns with uneven heat distribution and often many were so soft, they would sometimes be not fit for exterior use. The workmen would try to set aside the uneven fired for interior use (They tended to have a salmon color to them.) but many would get used for the exterior anyway. These are the deteriorating bricks seen so often on older historic structures. In the end, historic bricks were less rigid, more porous which would contain water inside the bricks. Modern bricks contain as little as 10% water while the older bricks will have as much as 35 percent for the salmon-colored to 20 to 25 percent for the even-fired ones!
A common mistake today is to put in modern mortar which traps the water inside, add undue pressure to the brick and the result is again a crumbled mess. When picking out old bricks, clinking them together is an excellent test – if they sound a high-pitched ringing sound, they’re evenly fired and are hard. This isn’t a perfect test but pretty good for picking out duds from a pile.
Now comes the cleaning. It really depends on what you are trying to remove. Keeping the weeds out of the bricks is often a hand-picking process but using chlorine bleach at 10 parts hot water is very effective. Some use generic vinegar but often the store-bought variety is too diluted to be effective. Of course, for the non-environmentally sensitive, there is always Weed Be Gone. Just make sure none of it reaches the city’s sewer system!
If it’s to remove plants and moss, use the chlorine bleach approach or simple scrubbing with a bristled brush. Tight spots can often be reached with a garden shear. If it’s that efflorescence, water drenching and a stiff bristle can do the job. If it’s stubborn, I recommend a masonry efflorescence remover that you can easily pickup at Lunt & Kelly’s*. If its oil stains or discoloration, naphtha or trichloroethylene are the most effective. Again, make sure none of these cleaners reach the city’s sewer system. Sparkling clean brick sidewalks and a polluted Merrimack River is not a good balance.
Okay, you took care of the brick. What about the granite curbs or granite blocks if they are in your driveway? Granite is called a siliceous stone and is hard and durable. It is best to use a stone poultice to remove stains. You can boost the power of a stone poultice by adding a little all-purpose cleaner, as long as it doesn’t contain chlorine bleach. If you just want to clean the granite which includes removing moss and organic matter, use a stone cleaner that has phosphoric acid.
Now, after all that cleaning, you may end up disappointed as the granite surface may end up rather lackluster. You can purchase a stone enhancer which will bring a more saturated look to the stone. Some even come with a sealer which adds stain resistance.
As you can see, if you end up doing a thorough job; you’ll boost the property value of your home and put a big smile on all the employees of Lunt & Kelly’s*.
* Yes, I know they are called Kelly’s True Value. For locals, they will always be called Lunt & Kelly’s.