Tuesday 29 March 2016

Densifier for Garage floors.... As an option?

updated 16 April, 2015 by Shea 37 Comments

Concrete densifier with sealer on a garage floor

A new trend that is slowly working its way into the garage is the use of a concrete densifier sealer on the garage floor.  Densifiers have been used on occasion in the garage for a variety of reasons, but rarely as an actual finished garage flooring treatment.  So why has there been a gradual increase in its use and popularity for the garage floor?
The reason is the addition of silicone and siliconate agents in some densifiers to act as a sealer.  This helps to create not only a water repellant floor, but one that is resistant to liquids in general.  So let’s take a closer look at how a concrete densifier with sealer on your garage floor may be beneficial for you.

Concrete densifiers have been around for decades.  They are a concrete hardener and in the flooring industry used primarily for concrete floor polishing, abrasion resistance, anti-dusting, and in some cases to harden softer concrete surfaces before grinding.
Lithium densifiers are the most common choice used for garage floors. This is due to their ease of application and less reactive properties to carbon dioxide which can create a whitening effect on the floor. Unlike sodium densifiers, lithium densifiers also do a good job at repelling road salts. Once applied, the concrete retains its natural matte look.
When concrete cures, bleed water makes its way to the surface increasing the water to cement ratio, laitance content, and fine aggregates.  This is what helps to make the surface of concrete smooth, but it also creates a surface that is softer than the underlying cement.  When a densifier is introduced, the chemical reaction increases the surface strength of concrete from an average of 20% to 40% depending on the original pour and finish of the concrete.
It does this in two ways.  The densifier is a water based chemical solution that first works by penetrating into the surface of the concrete and reacting with calcium hydroxide to produce calcium silicate hydrate (CSH).  This is the substance that gives concrete its strength.  Next, the CSH that is produced fills the open pores of the concrete increasing its density.
It’s important to note that concrete densifiers are non-film forming, meaning that they don’t leave a topical film on the surface to protect it from liquids and staining.  This is why they haven’t been used much as a finished product for garage floors – until recently.
The addition of silicone and siliconate agents in densifiers creates a waterproofing agent right at the surface of the concrete.  This allows the concrete densifier to act as a sealer for your garage floor by repelling water, oils, chemicals such as road salts, and other fluids.  They can also be used over stained concrete.

Are they 100% impervious to stains and chemicals?  No, but if you don’t allow spills to sit for a long period, they will generally wipe right up with little if any scrubbing necessary.  Be particularly careful with solvents that can stain, as their resistance to them is minimal.

Which Concrete is best?

I'm often asked which concrete is best? And isn't stamped Slippery? Given 3 choices. Stamped Concrete, Exposed Aggregate, Broom Finish(coloured or plain). With broom finish the broom creates roughness and openings in the surface that allow salt and water to permeate the surface and find light weight or iron stones that create popouts. Read more on popouts at srmca.org. Popouts then gather salt residual that can reactivate with rain all summer and turn into shaling. We highly recommend Acrylic Sealer to slow or stop this. Exposed Aggregate has already had the surface paste removed, (the process includes Acrylic sealer) so stands up well in our climate, stamped doesn't have those pores that absorb salt, and is sealed with Acrylic. If looked after stamped first exposed aggregate second can look best. There are situations where stamped shouldn't be used with lots of slope, but if done right, gritted properly, the look can outweigh the few slippery days, plus a small pail of sand can be used to eliminate slippery on those days when required. But we love all concrete at Rockscapes when looked after. Check us out at www.rockscapes.org. #‎yxe #‎saskatoon‪  #‎trustedsaskatoon #‎concretecontractor #‎saskatoondriveway #saskatoonconcretecontractor


Monday 28 March 2016

Paving Stones vs. Stamped Concrete

Before I get into a bit more about the differences between “Concrete vs. Pavers”, we should mention the difference between “Concrete Contractors” and “Landscape Contractors”.

Contractors for either of the above mentioned products could be described as experienced long term contractors, with lots of equipment and experienced staff, versus someone new breaking into the business, perhaps under capitalized and with limited experience. Methods employed by these two installation crews can vary greatly. This affects the pricing and quality of the project.

Ground Preparation – excavation depth, tamping pressure and tools used, rebar (rebar size and spacing for concrete are crucial)

Pavers/Concrete – There are 3 types of Pavers and numerous qualities of Concrete

Concrete Pressure Relief Joints – Depth of cuts and experience dictates where cuts should be.

Concrete Sealers – There are many more sealers on the market now. Silicate Based, Acrylic, and water based densifiers are common with some contractors. Prairie Concrete in Saskatoon is a good source for your information on Sealers.

I believe that most Canadian suppliers are selling “Concrete Pavers”, although there are “Brick Pavers”, mostly shipped from the USA. Both pavers are cast under heat, making them strong. The brick pavers are made from clay and shale. They are a little more prone to efflorescence, typically brick pavers are available mostly in red or reddish brown earthy tones while concrete pavers come in a variety of colours.

Concrete purchased by reputable companies is normally a minimum 30mpa, or Dura mix. Dura mix is a standard trademark used by Saskatchewan Redi-mix plants, meeting a minimum standard used in our freeze thaw climates. With the addition of colours to mixes, sometimes the mix design in your concrete may be optimized or modified slightly.

My company, Rockscapes Concrete Service has been installing stamped concrete and Decorative concrete projects and / or Plain Broom finish driveways in and around Saskatoon for almost 20 years. We are a reputable standard in this industry. There is no doubt in my mind that properly maintained concrete driveway or patio can stand up very well. Notwithstanding, a concrete slab, in high water table area, high clay saturation in a freeze thaw climate will have movement and crack. But the concrete slab will stay reasonably flat, and if the rebar was positioned and lifted, and the concrete was of a good quality and maintained through the use of sealers and rinsing off the road-salts in spring, it should still wear very well.

The biggest complaint with paving stones seems to be ground movement. Once the pavers start to move and separate they sink, and gaps occur. My understanding is that most Paving Stone companies have maintenance or are willing to re-lift the pavers. I believe most of them do offer a warranty for this service. Paving stones are a very hard product and stand up well to salt damage without the use of sealers. A good size paving stone driveway may take a week or longer to install. It would be costly to be forced to continually pay and have them come and level your paving stones. This may be one of the reasons you will see more driveways made of concrete. Price is another factor!

Cost Comparisons – Pavers vs Concrete

My understanding of Paving Stones pricing and Concrete pricing is just a rough guideline, there are many factors that can affect this.

·      The grade of the land, how much fill needs to be moved or added.
·      Location and access are factors
·      Can equipment be used or is the job all hand work
·      How complicated is the job, is engineering required?
·      Are custom steps involved in the project?
·      Patio’s and Pool decks are often more difficult, and smaller square footage. Usually priced higher for this reason.

As a rough guideline:

Plain Broom Finish Concrete Driveways - $8.50 - $11.00 per square foot.
Plain Broom Finish Concrete Patio’s - $12.00 - $15.00 per square foot.

Stamped or Exposed Aggregate Concrete Driveways - $11.00 - $14.00 per square foot
Stamped or Exposed Aggregate Concrete Patio’s - $14.00 - $18.00 per square foot

Paving Stone Driveway - $10.00 - $15.00 per square foot
Paving Stone Patio - $17.00 - $25.00 per square foot

John Groves is the owner of Rockscapes Concrete Services in Saskatoon and these are his express opinions based on experience and feedback. John can be reached at 306-220-2333 or www.rockscapes.org
#yxe #saskatoon #trustedsaskatoon #saskatoondriveway #saskatoonconcretecontractor #rockscapes