Driveway Sealing

Clear Green do offer a driveway sealing service. However we do feel that driveway sealing has its limitations though that you, as a customer, should be fully aware of in order to assist you in making an informed decision as to whether to seal or not. The following information is based on our experience of applying sealers to driveways and patios.

SEALANTS

Sealants for paving really established themselves in the decorative (pattern imprinted) concrete market where they are an essential component of the finished work. From there, they moved into the block paving market, initially as stain preventers and, for concrete pavers, as a colour enhancer.  The way sealers are sold and marketed strongly gives the impression to prospective customers that, once applied, the driveway or patios will be virtually maintenance free for years to come - particularly from the build-up and  growth of weeds.  However, in our experience we've found this isn't necessarily the case.

Whilst it is true that a good quality sealer will initially hinder or prevent the growth of weeds and will stabilise the jointing sand, dirt, dust and detritus will still form on the surface of the driveway or patio (on top of the sealant) - you can't stop it, it's airborne. Over time biomatter, then weeds, WILL form in this build up of dirt on the driveway and, once they have an established root system, will start to penetrate down into the jointing sand, exploiting any cracks that may have started to appear there over time and gaining further growth. We have seen sealed driveways where there has been a thin layer of green algae over fairly large areas of the surface on some driveways which was growing on top of the moss already forming in the joints. In addition sealer WILL get worn away in high traffic areas, particularly by vehicle tyres on driveways - we've seen no end of driveways where this has been the case and the wheel tracks of the homeowners' cars can be clearly seen where they have worn the sealer off over time. This then leaves those particular areas of the surface in more or less their original, unsealed state, and totally exposed to the growth of moss, algae and lichens.

It is important that the right, good quality, sealant is selected if sealing a driveway or patio area is the preferred option. Some sealants have no visible effect on the appearance of the paving whilst most impart a permanent 'wet-look', with either a gloss or a matt finish. The range of sealants is quite large but the four main types are;

• Water-based Emulsions
• Solvent-based Acrylics
• Moisture Cured Urethanes (aka SPPU's - Specialist Pre-Polymer Urethanes)
• Hydrated Polymer Glues

The most commonly specified sealants used in Britain are acrylic and urethane based sealants:

Acrylic sealants are typically used on PIC (pattern imprinted concrete) and residential paving. They are relatively cheaper, but usually require repeat treatments at annual intervals to maintain their properties. They aren't as flexible as urethane sealants and can be adversely affected by oils and petrol.

Polyurethane sealants are more reliable giving longer protection, but are more expensive. They can repel oils and paints, including light fuel oils such as petrol and paraffin, prevent staining and virtually eliminate weeds until they break down. They will also bond the jointing sand to help reduce loss through erosion.

There are, of course, some very strong advocates of sealants who maintain that their application is highly beneficial. Often these advocates are those with a vested interest in their success such as manufacturers or contractors who make significant revenues from applying them as a service.  Some of these advocates might argue that those who question the claims made for sealants either haven’t applied them properly or haven't done so in the right conditions.  This isn't the case though as, whenever Clear Green apply a sealant, the manufacturer’s guidelines are always followed to the letter for what is, after all, a fairly simple process and straightforward  job.

COSTS

Sealants are not cheap and good quality ones are relatively expensive. Even the budget versions you can purchase off the shelf at your local DIY outlet are not a particularly cheap option when you consider the coverage and the area of driveway or patio to be treated and the fact that multiple coatings may be initially required. 

Professional sealants range in price from in excess of £100 - £500 per 25l drum and give an average covering of 5 m2/l and that's the cost price to the contractor. In the normal way of business a lot of contractors will then add a margin to the cost price to give a sales price to the customer, making it more expensive.  While these sealers are supposed to last between 3-5 years, in our experience the reality its more like 2-3 years, especially in high traffic areas.

If you were to calculate the size of the average driveway and the fact that multiple coatings may be needed then the cost of the sealant alone can become quite expensive, without factoring in the cost of application or the cost of cleaning the driveway/patio initially. 

Another important point to remember is that, whilst good quality professional sealants will prevent and deter weed growth for a period of time, they will eventually break down allowing weeds to establish and grow. At this point the decision then becomes one of whether to re-seal or not and the expense that once again incurs.

BOTTOM LINE

Clear Green do provide a sealing service. However, we believe it is not an "apply and forget" approach that the customer needs to adopt if their expectations are to be met, which can often be high. For the customer to reap the rewards of what can be a reasonably high outlay, we believe they need to be prepared to carry out periodic maintenance - brushing off all the dirt, leaves and detritus as well as washing down their driveway or patio with a hose every month or two (not pressure washer as that will erode the sealant), in order to keep the sealed surface in as clean a state as is realistic. Without this the sealed surface will start to look dirty, will harbour dirt and biomatter in the joints and cracks, and eventually will have moss and weeds growing on that dirt which, to us, would defeat one of the main selling points in having the driveway or patio sealed in the first place.