What are roof core samples?

Assume you are considering purchasing a large commercial, industrial or residential building that has been operating since 1990. Naturally, it has a functioning roof, but as the buyer you’ll have a bunch of questions about it. For instance, what is it made of? What condition is it in? How many layers are stacked up on top of each other? Has it been well maintained?

An excellent way to answer all those questions is to take a core sample. There are several ways to take that sample. For instance, the CRREL cutter saws a 2” diameter hole in the roof. The “core” can be pushed out of the pipe and its components examined. The round hole is easily patched. Other methods of taking core samples include: cutting with an ax, knife and/or insulation saw, or with a reciprocating saw. Each method has advantages and disadvantages depending on how large a sample you need to take, how deep you need to go, etc.

Once the core sample is taken, it can be analyzed for the following details:

• Layers – how many layers are in place?
• Materials – what are the different layers made of and what are the weights of each layer?
• Thickness – how thick is the current roof system?
• Slope – is the slope on the roof in the insulation or in the roof decking?
• HazMat – are there hazardous materials in the layers (like asbestos)?
• Deck – what is supporting the roof system?
• Water – is there water trapped in the roofing material?

Analyzing these factors can help you make the decision to buy. You will probably want to check local building codes to make sure what you discover is up to code. For instance, buildings with more than two roof systems usually require a complete removal down to the roof deck to meet code. The last thing you need is to buy a building that immediately needs a new roof. It can also help you discover if there are hazardous materials you might have to dispose of in the future. In addition, the R-value code requirements might have changed since the initial build, so you might be required to upgrade as soon as you buy.

If you’ve already purchased the building, a core sample will help you create a roof asset management system. This online tracking system will help you schedule repairs, create future maintenance schedules and budget for repairs and replacement.

NOTE: If you, as a building owner or buyer, are seeking accurate pricing for roofing projects, it is a good idea to insist that your professional roofers obtain a core sample to gather sufficient information to provide accurate quotes.