The best sealer for broom finished concrete will depend on what you want the broom finished concrete to look like once sealed, and what you need the sealer to offer in terms of performance.
The most popular type of sealers for broom finished concrete are penetrating concrete sealers. Penetrating concrete sealers absorb into the surface of the concrete where they chemically react below the surface to protect the concrete from within the pores. The two main types of penetrating sealers are concrete densifiers and water repellent sealers.
Water Repellent Sealers for Broom Finished Concrete
Water repellent sealers penetrate into the surface of the concrete for form a hydrophobic barrier within the pores that reduces the absorption of water and other liquids on the surface. Depending on the water repellent, the concrete will remain unchanged, or the concrete will be left with a wet look (darkened appearance).
The most common phrasing you see on water repellents is silicone, siliconate, and Silane-Siloxane. While they are all made from similiar chemicals, they vary significantly in terms of life and performance. The largest difference from one product to the next in the same category is going to be the percent of active materials. For example, the SX5000 is a 40% solids formula and the Thompson’s Water Seal is 2-8% solids. The SX5000 has up to 20X more active materials so you will see better protection, longer. The Thompson’s Water Seal is still a great product with great reviews, but you will expect to recoat much sooner with Thompson’s than you would with the SX5000.
Now, Siliconate water repellents and Silane-Siloxane water repellents are very similiar, but the life and application is a little different. Siliconate water repellents like the SC25 are designed as single coat applications. If you attempt to put down a second coat, the first coat will cause it to bead off the surface. It is very aggressive from the start. You will recoat every 5-7 years. Silane-Siloxane water repellent sealers take up to 72 hours to start reacting and require two coats, but they last 7-10 years (high solids solutions).
To be honest, there isn’t enough of a difference between Siliconate water repellents and Silane-Siloxane water repellents on broom finished concrete to say one is better than the other. The brand and the actual product itself will make more of a difference than the category of sealer. Siliconate wate repellents are very popular on broom finished concrete simply because they require one have coat and start working immediately. Siliconates are also known to work phenomenally well on white or light concrete because there are no chances of having dark spots form from over application. If you are considering a Silane-Siloxane sealer instead, just look for something with 20% or more solids, and go with a reputable company that has great customer service.
Water Repellent Sealer Reviews
- Armor SC25 – Siliconate water repellent sealer with an average 5.0 star review.
- Eagle Natural Seal – Low solids water repellent with an average 4.0 star review.
- Armor SX5000 Concrete Sealer Review – DOT approved Silane-Siloxane water repellent with an average 4.8 star review.
- Siloxane PD Concrete Sealer Review – High solids siloxane water repellent with an average 4.5 star review.
- Okon S-20 Concrete Sealer Review – High solids water repellent with an average 4.0 star review.
- Thompson’s Water Seal Concrete Sealer Review – Low solids water repellent with an average 3.2 star review.
- Armor WL550 – Wet look water repellent with an average 5.0 star review.
Concrete Densifiers for Broom Finished Concrete
Concrete densifiers are very different from water repellent sealers. Concrete densifiers chemically react below the surface to from CSH (calcium silicate hydrate) in the pores. In sum, they form crystalline barriers in the pores that help to increase the density, and therefore strength, of the concrete. All densifiers are the same – they spark the same chemical reaction in the concrete and the chemical reaction is what determines the size and amount of CSH that forms. Once the chemical reaction takes place, there is no longer any sealer left. All that is left are the crystals. Concrete densifiers do not bead water and they do not prevent or reduce water absorption or surface stains – they are only used to increase the strength and density of the concrete.
Densifiers can be used alone, or a week before the application of a water repellent sealer. If you intend to apply a coating, be sure to check with the coating manufacturer first. Densifiers reduce the size of the pores and most coatings need open pores to bond. It is always safe to check with the manufacturer before sealing.
The two most popular types of densifiers are sodium silicate densifiers and lithium silicate densifiers. They both spark the same chemical reaction. The molecule size is larger with a sodium silicate and smaller with a lithium so sodium silicate sealers are popular on porous surfaces, and lithium silicates on dense.
While all densifiers create the exact same chemical reaction, you will notice that some are diluted and others aren’t. Silicates must be applied to the concrete at a certain percent solids. Most come already diluted with water and some require you to add water before applying. Concentrated densifiers are more cost effective for large areas, but again, they all produce the same chemical reaction.
Sodium Silicate Concrete Densifier Reviews
- Armor S2000 Concrete Sealer Review (concentrated)
- RadonSeal Concrete Sealer Review (pre-diluted)
- Stone Technolgies X-1 Concrete Sealer Review (pre-diluted)
- Ashford Formula Concrete Sealer Review (pre-diluted)
Lithium Silicate Concrete Densifier Reviews
- Armor L3000 Concrete Sealer Review (concentrated)
- PS103 Concrete Sealer Review (pre-diluted)
- Lion Hard Concrete Sealer Review (pre-diluted)
Gloss Sealers for Broom Finished Concrete
If you want a wet look, low gloss, or high gloss finish then you want an acrylic sealer. Acrylic sealers will coat the surface of the concrete to leave a visible surface film. Most acrylic sealers need to be re-coated every 1-3 years, but they are a great way to bring new life to a concrete surface.
The two main types of acrylic sealers are water based acrylic sealers and solvent based acrylic sealers. Water based acrylic sealers will enhance the concrete with a gloss without darkening the color of the concrete, and solvent based acrylic sealers will darken the color of the concrete and enhance it with a gloss.
If your concrete already has an acrylic sealer down and you are looking to re-coat, you have to remain consistent. If you have a water based acrylic sealer down, you want to re-coat with a water based acrylic. If you have a solvent based acrylic sealer down you want to re-coat with a solvent based acrylic. If you mix the two types of acrylics it will result in failure of both acrylics.
Water based acrylic sealer reviews:
- Seal-Krete Clear Seal Acrylic Sealer (average 4 star review)
- Armor WB25 Acrylic Sealer (average 4.9 star review)
Solvent based acrylic sealer reviews:
- Eagle High Gloss Sealer (average 4.6 star review)
- Armor AR350 Wet Look Sealer (average 4.8 star review)
- Armor AR500 High Gloss Sealer (average 4.9 star review)
- Enduraseal SB Acrylic Sealer (average 4.5 star review)