Your quest is to find the best foundation repair contractor to perform your house leveling project. You wonder about what type of shims are going to be used for the repairs to your crawl space foundation. Which is better: wood or steel shims or does it matter?
At Anchor Foundation Repair, we know it matters very much what style of shim gets used for repairs to a crawl space foundation. We have seen hundreds of homes that have been shimmed using the inappropriate style of shim and observed firsthand how a bad shim choice can affect your home and floors down the road.
I’m gonna be honest here and point out that yes, I am biased on this topic. There is a clear winner in the battle of the shims in my mind and that’s wood.
But in this article, we will present the pros and cons of each style of shims as fairly as possible, while also describing the shim types available for foundation repairs.
Shim Types for Home Foundations
Shims are used in various aspects of home construction and are a key component in home foundation repair. Here’s my personal definition of a shim developed in another article defining shims used in slab foundation repair:
A shim is a thin piece of material used to make slight adjustments between home elements, including foundations. Shims are inserted between larger parts to fill gaps, level, adjust, and make things fit properly while maximizing alignment and support.
More specifically for crawl space foundation types like pier and beam or block and base homes, a shim is a small piece of material that allows for precise fitting and support of the home’s foundational structure.
There are several material choices that shims are typically made from:
- Wood
- Metal
- Plastic
Wood shims are typically made of cedar shingles and are roughly 8 inches by 16 inches in size with some variation and tapered.
Metal shims are typically made from steel and are approximately note card sized at 3 inches by 5” inches. They are not tapered but are available in various thicknesses from ⅛ to ½ inches thick.
Plastic shims are the least popular choice and are more commonly used in other home construction projects not related to foundations. So, we will primarily focus on wood vs. steel from here on out.
Pros and Cons of Steel vs. Wood Shims
The main role of shims in the crawl space house leveling process is to allow for proper support and spacing to the wood beams or sill that create the foundation of the home. Shims are also there to disperse weight and maximize the surface area being supported between the sill beams and the floor structure.
Now we will break down the pros and cons of steel vs. wood shims based on how well they can perform this function in the long term.
Pros and Cons of Steel Shims
PRO: steel is resistant to rot and termites
PRO: strong and great for slab foundation repairs
CON: small surface area and limited thickness options
CON: can create humps in floors on crawl space homes due to size and thickness limitations
CON: rigid and inflexible against softer wooden floor structure materials
Pros and Cons of Wood Shims
PRO: lightweight and easy to manipulate and use
PRO: larger size maximizes support to sill beam and distributes weight better
PRO: very precise due to the tapered edge, no thickness limitations for a snug fit
PRO: more flexible to “give” along with other wooden components of the foundation
PRO: cedar material is rot and termite resistant
CON: expensive for basically just being a small piece of wood
CON: it’s a con that there are no other cons to list
What Shims Are Best for a Crawlspace Foundation?
Based on the pros and cons listed above, it’s fairly clear that wood shims are the better choice for use in crawl space home foundation repair. Specifically, kiln-dried red cedar is what is best and what Anchor Foundation Repair chooses for all house leveling projects.
We use steel shims all the time for slab foundation repairs because they are great for that so we don’t hate them or anything. We just feel very strongly that wooden shims are the *only way to go* for a pier and beam or block and base foundation leveling project.
What’s More Important in House Leveling Than Shims?
Now you know that wooden shims are our No. 1 choice for crawl space homes. Don’t get me wrong, shims are important but probably not the biggest concern for most homeowners because you won’t ever see your shims.
What you might be more concerned about at this point is the warranty policy for house leveling work. We can’t tell you about any other company’s warranty, but we can tell you about ours . . .
At Anchor Foundation Repair, we have leveled hundreds of Brazos Valley crawl space homes since 1985 and have seen it all when it comes to house leveling foundation repairs. Our warranty policy is different for crawl space homes than it is for slab foundations.
Maybe your next article should be: Does Anchor Foundation Repair Have a Warranty for House Leveling? *Spoiler alert* the answer is yes, we do have a house leveling warranty, but there’s more to read about so check it out.