What Type of Joint Sealant Should You Use on Your Concrete Slab Floor?

Posted on: 30 March 2017

Flooring made of concrete slabs is exactly as tough and durable as you would expect, but even these incredibly redoubtable floors can become damaged in certain circumstances. The edges of your slabs are particularly vulnerable, as forklifts and other heavy vehicles and loads passing over these edges can cause them to crack and crumble without suitable reinforcement. The gaps between concrete slabs can also pose a problem if left unprotected, allowing rain and moisture to penetrate the floor and dramatically undermine its strength and stability.

Happily, there is a neat solution to both of these problems -- have the gaps between your concrete slabs sealed with a suitable concrete joint sealant. However, not every variety of concrete joint sealant is created equal, and there are two specific types of joint sealant widely available. Each of these sealant types is more suited to different sealing tasks. As such, it's important to ascertain which type of joint sealant is right for your needs before you hand over your cash.

Impregnated foam sealants

Impregnated foam sealants consist of solid, pre-formed foam gaskets, which are inserted between the gaps between the slabs in your concrete floor. Once installed, these gaskets expand to fill the gap, providing a durable, waterproof seal between your slabs.

The chief advantage of impregnated foam sealants is how quick and easy they are to install, and even the largest concrete floors can be sealed with this method in a matter of hours. They are relatively inexpensive, and do not require professional expertise to fit. Unlike other joint sealants, impregnated foam sealants also provide considerable amounts of heat insulation, which can be particularly useful for preventing heat escape and keeping heating bills down in larger buildings.

However, they can be less durable than other sealant types that are allowed to dry and cure after installation. They can be replaced relatively easily due to their low price, but damaged foam sealant gaskets can crumble and become difficult to remove if allowed to degrade for too long.

Liquid sealants

These sealants are applied in liquid form, using applicator bottles similar in form and function to caulking guns. When applied to the gaps between your concrete slabs and allowed to dry and cure, they form a solid and durable seal between your slabs.

The seal created is capable of taking a tremendous beating from both weather and heavy loads. As such, they are ideally suited to sealing concrete floors in outdoor environments, such as patios, pavements and driveways. They are are particularly well suited for sealing irregular gaps and cracks, such as those found in crazed paving. Liquid sealants also tend to be less labour-intensive to install than impregnated foam sealants, since sealant can easily be added or taken away from required areas before it dries in place.

Liquid sealants are, however, about as messy as to apply as you can imagine, and you may wish to call in professional sealing services for best results. Liquid joint sealants are also ineffective when applied to partiuclarly wide gaps between slabs, since a dried seal is at its strongest in a narrow space where slabs can compress it into place from both sides.