The Program

Public Works’ goal is to apply a surface seal to more than 150 blocks annually throughout the City as an efficient and cost-effective way to prolong the life of our streets. Surface sealing 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. Surface sealing takes two days to complete on a block, compared to several days/weeks for full roadway reconstruction which can include street base repairs and repaving. The first application of surface sealing is applied followed by a second application, typically about a week after the first application.

The Polymer Modified Slurry Seal is a liquid-oil and crushed rock mixture that is applied in two applications and requires about two to four hours to dry in moderate weather conditions. Once completely dry, residents are able to walk and drive on it safely without tracking it onto sidewalks and driveways. 

FALL 2024: NEW SURFACE SEALING DATES IN BALBOA PARK, INGLESIDE, EXCELSIOR AND CAYUGA TERRACE NEIGHBORHOODS STARTING OCTOBER 30TH - SEE SCHEDULE HERE.

How it's applied

Surface sealing is applied in dry, moderate to warm weather conditions. The process includes the use of a large steam-roller like truck that pours the surface sealing material onto the street. Workers will then use a long squeegee-like tool to spread the material evenly across the street.

What to expect when it's finished

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, surface sealing 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 surface sealing. We will schedule post-sweeping of the block a few weeks after the work has been completed to pick-up any loose aggregate rock. 

 Additional Information During Surface Sealing Construction

Residents/Merchants on the block will receive a notice 7 to 10 days in advance of the surface sealing 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.

Surface sealing work typically takes two separate days to complete.  The first application of surface sealing is applied followed by a second application, typically about a week after the first application. On the indicated date(s) the street WILL BE CLOSED to traffic, including bicycles, between 8:00AM to 6:00PM. Street parking restrictions may go into effect as early as 7:00AM 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 8:00AM on the indicated date(s). You may not be able to return to your garage until after 6:00PM. We will re-open the street sooner if the surface sealing 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 8:00AM.  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.

Work hours

Week Days (Monday - Friday) 8:00AM to 6:00PM. Parking restrictions may begin as early as 7:00AM on your block. Please see the "no parking" signs on the barricades. Weekend work may be allowed but none has been scheduled at this time.

Street restrictions

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.