Q&A for How to Install Asphalt

This is normal and shouldn't be anything more than a shadow. If they did it properly and if it's truly recent, they can come back and heat the area up to make it blend properly.

Asphalt is made up of four products: a man-made sand that's a byproduct of crushed rock, natural sand, crushed rock, and hot oil. All is mixed and heated to approximately 300 degrees, which combines to create the asphalt.

The surface has to be cleaned by air compressors, and all debris and any loose or obstructive material removed thoroughly. After cleaning the surface, a prime bitumen coat has to be applied in accordance with engineering specifications.

Yes. Before laying asphalt, MC-1 should be applied as the primer. Before spraying, MC-1 should be heated to reach a minimum temperature of about 80 degrees centigrade (not more than 100 degrees centigrade). Spray MC-1 to completely cover the sub-base surface and it will appear black. Allow MC-1 to completely adhere to the surface until it's dry to the touch. Finally, lay the base material.

Yes, or else it wont be strong enough to hold the force.

Just one layer 2 to 3 inches deep will suffice. Put it down on gravel, and make sure if it's near your home, you slope the asphalt away from the house to ensure rain water doesn't get to your house.

It depends on what is under the sheet. If you aren't worried about the ground underneath, then no. If you are, then most certainly.

Yes, but it is a lot more difficult. The asphalt cools off quicker, and if it cools off too much before you're done compacting, you won't get a full compaction, leaving yourself with rougher-looking, weaker asphalt.

No, there is too much movement in concrete slabs which will crack the asphalt.

Yes. The portion not over concrete needs replacing.

Spray diesel fuel on the drum; this creates a non-stick surface. You'll have to do this multiple times.

Water will cool the asphalt. This can lead to insufficient compaction and faster wear. Surfaces receiving asphalt pavement should be dry.

Most asphalt proportions vary with liquid asphalt cement to material. Some have a dry mix (with less asphalt, which makes it easier to work with, but will most likely break up faster) and some have more of a wet mix (with more asphalt, which makes it harder to work with, but will hold up better over time). Then you have different types of mix itself: Binder, which is normally a base for roads; Finish, which is what you normally see as a top coat over binder on roads and is used for basically everything else; Skinny, which is used to cheaply resurface existing roads to fill in holes while putting just enough mix down to level the road; and Specialty mixtures that are used for running tracks, tennis courts, etc.

This raises major red flags. The first possibility is that the mix was put down when it was too thin with weeds, grass seed, or roots underneath. It's also possible that the mix was too old. (If it's below 285-320 F, then it won't compact properly with the above issue.) The "contractor" may have used RAP (Recycled Asphalt Pavement) instead of fresh hot mix asphalt. It makes a great base to pave on when compacted, but can still have grass or weeds in it from when they tore or ground it up last. Finally, there's a possibility you might've gotten scammed with the fake "professional contractor" bit, or it might've been a legitimate company that just isn't good at laying down asphalt.

Yes, very much. Asphalt should be between 285-300 degrees Fahrenheit when it is unloaded at the job site. If the mix is over 300 F, the liquid asphalt cement compounds have a high risk of evaporating, and if it is below 285 F, the mix will be weakened because it will not join together as well when it is compacted.

If you install cold asphalt from the asphalt plant, you will have a weakened surface if the mix is under 285 degrees Fahrenheit; the mix will not bond together when compacted. However, if you are talking about RAP (recycled asphalt pavement, also known as "cold millings"), then you could do that as a cheaper option to resurfacing a parking lot, driveway, or even a country road. It will not look as uniform as new mix, but it makes a good base if you want to put new asphalt over it or a cheaper surface as long as it is well compacted.

It usually doesn't matter unless it is extremely hot or extremely cold. The warmer it is, the longer it will take the asphalt to set (usually a couple hours in 70F/30C). The colder it is, it may not adhere as well to any underlying surface or substrate. This all depends on the thickness of the surface you choose and the density/material of the asphalt.

You shouldn't need to apply a sealer to a fresh asphalt surface. Let it set first, and then a sealer may be applied (usually after three months or more). Ask your installer for recommendation, but a sealer may not adhere as well to fresh asphalt.

If the asphalt is still 300 F and there is just a sprinkle or light drizzle, then yes. Anything more and I would say no. Liquid asphalt cement is mainly made with petroleum products and it will dissolve if it is in contact with a lot of water while setting up (water on the drums of a roller is fine). The base also needs to be dry. If you pave over a puddle, then the water will break down the asphalt from underneath, producing a pothole over time. Diesel fuel will do the same thing (on tools to prevent sticking is fine, but don't put diesel on them over fresh mix).

Asphalt is held together by Liquid Asphalt Cement, which is made of petroleum products with some other chemicals mixed in.

Yes. Usually an installer will mill any surfaces that are raised or uneven, then any existing surface will be cleaned with air, then a tack material which will bond the old surface to the new asphalt is applied. It is recommended for a good bond to groove the old surface before the tack is applied.

You should wait 90 days before you seal asphalt. The sealer will trap the oils and cause it to crack and fall apart sooner. Let the asphalt cure before sealing.

Yes. In the paving world we call it an "overlay", where you put down another layer of asphalt on top of an existing layer. It is cheaper than removing the old layer. However it sets the new "lift" (another layer) up for failure due to prior cracks, low spots (bad drainage), weakened areas, etc.

That depends on the nature of the road; traffic volume, function, economy etc. Also, it will depend the nature of the sub-base. For low traffic volume pavement base course where the sub-base layer is normal soil ( not clay or watery) will be around 15cms and asphalt course to be 3 to 5cms.

Yes, that is resealing. Care should be taken on the extent of old asphalt distress.

It is generally not recommended with HMA. With CMA, i.e., with bitumen emulsion, it is possible.