Lintels can come in plenty of different materials and are able to suit different spans and wall configurations.
Do you know the different types of lintels available for the project you have going on? Knowing which lintel to use can save you both money and time.
This post is going to cover the different types of lintels with a focus on concrete and steel lintels. By the end of this short post you will know about two of the major lintel manufacturers on the market in the United Kingdom and how to select them based on the load conditions you have. If you are not based in the United Kingdom although the product types may vary the process for the selection will be the same.
As always, seek advice from a registered professional before doing any major structural works yourself. Removing load bearing walls can cause major stability issues and potentially put lives in danger if not done responsibly.
At the end links will be provided to data sheets/selectors by the suppliers with an explanation as to how to use them and select your lintel.
So What Is a Lintel? And Why Do We Use Them?
A lintel can be thought of as a beam, it spans a gap and in order to do that must have the capacity to support the load that would of previously been acting on the gap. Lintels are generally used for residential dwellings (houses) and for smaller openings. Larger openings will normally use beams made from steel or concrete due to the increased capacity required. For small openings lintels can be more cost effective. They come in a multitude of material such as sandstone, steel, wood and concrete.
We can find lintels all over the place. Now let us take a standard house. Have a look above the windows and doors, the external view of a terrace house is a great way to find them. Internal lintels may be concealed by finishes as they are not exact decorative.
How Do We Select Lintels?
Selecting a lintel is not a difficult task, we need to look at three key pieces of information and from that made our decision. Load, Span and Wall Configuration.
Load – The lintel must have sufficient capacity to carry the load and therefore bridge the span. The load is provided in datasheets from the suppliers. These sheets made our job really simple!
Span – Very much related to the load, the larger the span, the greater the bending in the center. The datasheets provide either one of the following options. The maximum span due to a set weight criteria or the maximum bending and shear resistance of the section. Sometimes both. When we go through the examples at the end, you can see how to calculate the bending and shear forces, the most important aspect is understanding the actual load.
Wall Configuration – This is arguably the most important part in the decision making. We need our lintel to fit onto the wall. Lintels come in different thicknesses and shapes to marry up with common wall types. Wall configurations or types are either cavity (inner and outer leaf with a gap in the middle) or a single leaf.
Fire Resistance of Lintels
Another major consideration when choosing a lintel is the fire resistance or protection that they offer. When proceeding with a design we need to look at either the building regulations or clients specification to determine the requirements (some clients may have significantly higher requirements than building regulations may recommend). From this we can match the product for the outcome. Lintel suppliers will state the fire protection that can be expected making it quite simple to ensure everything is in order.
Note, different authorities/states/countries have there own requirements with respect to fire protection. Therefore, if you are here for some DIY/home improvement project please check the requirements for your location. In England for example, local councils can provide all the guidance you need and most of it can be found on their respective websites. Can’t find it? Send them an email. Personally, I’ve always found them to be helpful.
Now we have the knowledge on the background of lintels, we can look at some suppliers. I can only advise on suppliers located in the United Kingdom as these are the only types I have actually specified for projects.
Common Lintels in the UK – Catnic Lintels
Tata Steel have a large product range, one of which is called ‘Catnic Lintels’.
The product range cover all types of walls including cavity walls, single skin walls and corners. The lintel is made from austenitic stainless steel and is used to provide protection against corrosion. Two different types are available depending upon the environment, one for common environments and one for aggressive.
Common Lintels in the UK – Naylor Lintels
The second supplier we will look at is Naylor. Again, this supplier has a large product range than just lintels. The lintels are prestressed concrete. Check out this post for a little background on prestressed concrete.
In a similar fashion to the Tata Steels Catnic lintels, they have a lintel selector to aid you in choosing the correct lintel.
These lintels can also be used as padstones which allow steel beams to bear onto masonry and disperse the load.
My own personal approach is to use Naylor lintels for single skin walls and Catnic for cavity walls, however, as long as the lintel is strong (in terms of load) and abides by the your clients specifications feel free to chose any.
Deriving the loads probably the most important aspect when finding a cost effective solution. Professional advice should be sought out when calculating the loads that may be acting on a lintel.