Public Works is applying a micro-surface seal to more than 250 blocks annually throughout the City as an efficient and cost-effective way to prolong the life of our streets. Micro-surfacing preserves the asphalt pavement by protecting the surface from the effects of natural aging and the environment caused by inclement weather, excessive heat and the searing effects of the sun. It can extend the life of pavement at a fraction of the cost by restoring the wearing surface of a roadway and sealing off any moisture and preventing oxidation that can cause deterioration and require more costly repairs down the road. Micro-surfacing should take 1-2 days to complete on a block, compared to several days/weeks for full roadway reconstruction which can include street base repairs and repaving.
“Micro-surfacing” is a liquid-oil and crushed rock mixture that requires about four to five hours to dry under moderate weather conditions. Once completely dry, residents are able to walk and drive on it safely without tracking it onto sidewalks and driveways.
Micro-surfacing is applied in dry, moderate to warm weather conditions. The process includes the use of a large steam-roller like truck that pours the micro-surfacing material onto the street. Workers will then use a long squeegee-like tool to spread the material evenly across the street.
We will re-open the street when it's ready to sustain traffic. Please do not attempt to drive on it before then or you may damage the finished product as well as your vehicle. You'll notice that the finished appearance differs slightly from traditional asphalt paving which is dark gray and smooth; by contrast, micro-surfacing results in a gravely-textured brown finish. Over a period of three to four weeks the material settles to closer resemble streets with a basic asphalt finish. For the first several weeks after the material has been applied, you may notice some of the crushed rock aggregate will become loose. This is part of the curing process and can be expected with micro-surfacing. We will schedule post-sweeping of the block a few weeks after the work has been completed to pick-up any loose aggregate rock.
Schedule / Tentative Locations - revised 9/22/17
Residents/Merchants on the block will receive a notice about 7-10 days in advance of work.
Crews will place "no-parking" signs on the affected block at least 72-hours in advance of work. The "no parking" signs will alert motorists of the street closure and will indicate the specific date(s) and times the work will occur.
This work typically takes two days to complete. On the indicated date(s) the street WILL BE CLOSED to traffic, including bicycles, between 8:00 a.m. - 6:00 p.m. Street parking restrictions may go into effect as early as 7 a.m. on your block. Please see the posted date(s) and time on the barricades for exact parking restrictions. Emergency vehicles (fire trucks, ambulances, and police cars) will still have access to the street.
If you have a garage/driveway, you must exit your garage no later than 8:00 a.m. on the indicated date(s). You may not be able to return to your garage until after 6 p.m. We will re-open the street sooner if the micro-surface has cured.
Cars parked on the street during the construction work hours (posted on barricades) will be towed at the vehicle owner's expense.
Crews will work on several blocks each day, they may not arrive on your block until later that morning. Please do not park on the street if work hasn't begun at 8 a.m.
Sidewalk access will be available at all times and will not be affected.
Please do not water your lawn on the indicated dates or allow water to run into the street as this may delay the curing process.
Please do not walk, run, play, or ride your bike on the street prior to it being re-opened.
Week Days (Monday- Friday) 8 a.m. – 6 p.m. Parking restrictions may begin as early as 7 a.m. on your block. Please see the "no parking" signs on the barricades. Weekend work is allowed but none has been scheduled at this time.
*** Please Note: The schedule is subject to change due to rain, equipment breakdown, or unforeseen field conditions. Please see posted barricades for exact parking restrictions. Parking restrictions may vary per block. ***
Your street will be CLOSED TO ALL TRAFFIC ON THE INDICATED DATE(S) except for emergency vehicles. We apologize for the inconvenience and thank you for your patience as we work to improve San Francisco.
September / October 2017 Update
San Francisco Public Works
Telfer Pavement Technologies, LLC