
Preventing Alkali Burn By Applying Parapet Sealer to Masonry Surfaces
It’s a wonderful feeling seeing a freshly painted exterior wall in the colour of your choice. However that wonderful feeling can turn to disappointment and frustration if, over time, the paint on the walls starts to discolour, peel, chalk or bubble.
If this happens, these are signs of Alkali Burn. We’ll explain what Alkali Burn is in detail in this blog article. Alkali Burn causes deterioration in the paint, but the good news is it’s totally preventable! Read on to learn how to protect your walls and keep them looking beautiful with Shaves for years to come.
Common Causes of Alkali Burn
Alkali burn is a frequent cause of paint deterioration on walls. Below are some key factors that contribute to this destructive problem:
- Water penetration: Rainwater, underground water or condensation continually making contact with the wall.
- Incomplete curing: Relevant in new builds where the masonry hasn’t fully hardened. Fresh masonry still contains a lot of moisture and high pH salts. If the wall is painted too soon, the salts mix with water and travel through the masonry causing the paint on the surface to deteriorate.
- Cracks and structural issues: Cracks enable water and moisture to be deeply absorbed into the wall, making salt migration even worse.
How do You Know if Your Wall Has Alkali Burn?
You don’t have to be an expert to know when your exterior walls are affected by Alkali Burn. Simply look out for these 4 key symptoms:
- Discolouration and Staining:
The paint on your walls may look faded, yellowed, or develop streaks or spots that look different from the rest of the surface. - Bubbling or Blistering Paint:
If you see the paint has small raised areas that look like you can prick them, this shows that moisture and salts are seeping through the surface. - White Powdery Residue:
A chalky white substance, often called efflorescence, can appear on the surface of the paint. This is the crystallised salt that has come up from the masonry, making the paintwork look dull and powdery. - Peeling or Flaking Paint:
The paint is lifting away from the wall and may start to peel or flake off, especially in patches. This happens because the paint’s binder is broken down.
If your exterior walls are displaying any of the above signs of Alkali Burn, you will need to first sort out the source of the moisture – you may need to contact a professional water-proofer – and then the salts will need to be removed from the wall surface before painting again.
To neutralise the alkalinity of the salts, use an acidic solution of water and white vinegar. First, brush off the salts, then sponge on your solution and wipe the wall down. After the problems have been addressed, you can paint your wall with a suitable Dulux Alkali Resistant Plaster Primer and finish off with a Dulux Top Coat.
What is Alkali Burn in Walls?
On painted walls – Alkali Burn, also called pH burn, happens when the natural alkalinity of the masonry surface, such as concrete, brick or mortar, reacts badly with the paint.
Bricks/ mortar/ concrete often contain high-pH salts that dissolve in water and move to the surface, where they crystallise as the water dries. This process weakens the paint’s binder and causes it to break down over time.
How to prevent Alkali Burn with Parapet Sealer
A parapet is a wall mostly found at the edge of roofs and balconies. Parapets are often exposed to the weather and are therefore very vulnerable to water penetration, which as we’ve explained above, can lead to Alkali Burn. By protecting and sealing the parapet wall with a Parapet Sealer, you also protect the vertical walls below. Think of it as being like a gatekeeper wall.
How Does Parapet Sealer Work?
Parapet Sealer is a brilliant waterproofing product designed to protect masonry walls, especially parapet walls, from water damage. It works by creating a water-resistant barrier on the masonry surface (sealing it literally). This prevents water from soaking in and dissolving the salts in the wall, and therefore reduces the risk of pesky Alkali Burn.
Other reasons why you’ll love Parapet Sealer
- Built Tough: Reinforced with fibres for extra strength, durability and flexibility, making it ready for anything nature throws at it.
- Super Easy to Use: After prepping the surface and priming the wall, just grab a brush or roller and apply it on any wall—new or old! Check out this tutorial video.
- Lasts for Ages: Provides long-lasting protection against water damage, keeping your walls looking great.
- Built Tough: Reinforced with fibres for extra strength, durability and flexibility, making it ready for anything nature throws at it.
- Super Easy to Use: After prepping the surface and priming the wall, just grab a brush or roller and apply it on any wall—new or old! Check out this tutorial video.
- Lasts for Ages: Provides long-lasting protection against water damage, keeping your walls looking great.
We recommend Dekade Parapet Sealer for its exceptional quality and versatility. Find it at any Shaves Store (in Gauteng and KwaZulu-Natal). For surface prep, priming and application information for Dekade Parapet Sealer, click here.
They say prevention is better than cure. In the case of using a Parapet Sealer to protect against Alkali Burn in walls, prevention is certainly more convenient, cost-effective and easier. Pop into any Shaves store for expert advice or call us on 031 001 6315.