CHICAGO. FLAT & LOW-SLOPE ROOFS
Know your roof.
Layer by layer.
Flat roof core sampling reveals the materials and conditions beneath the surface—helping you plan your next roofing decision with better information.
ON SITE / A DMG CORE SAMPLING PROJECT
FROM A DMG PROJECT
Core sampling, in the field.
Your roof has a story beneath its surface. These project photos show how selected locations are opened and documented.
01. Select the test location
Marked test location with a Tramex RWS roof moisture scanner. Screening helps guide further investigation.
02. Make the test cut
A core cutter opens a selected location for direct observation of the roof assembly.
03. Examine the layers
Removed sample materials are arranged beside the opening for documentation.
04. Inspect the opening
A close view of the opening shows the exposed assembly at this sampling location.
05. Document the depth
A tape measure records the opening depth. Depth and materials vary across roof assemblies.
A CLOSER LOOK
A small opening.
A clearer picture.
A core sample is a small, controlled opening through selected roof layers. It allows direct observation of the assenbly at that location, beyond what a surface inspection can show.
DMG Home Services can discuss core sampling as a targeted investigation or as part of a broader roof assessment.
MATERIALS-Roof layers & composition
Document visible membranes, underlying roofing layers and other materials encountered in the sample.
INSULATION-Type & thickness
Observe insulation materials and measure the thickness accessible at the sample location.
CONDITIONS-Evidence of moisture
Examine the sampled materials for visible moisture and deterioration, with additional testing when appropriate.
PLANNING-A basis for next steps
Help inform repair, replacement or roof recover evaluations alongside the full roof assessment.
HOW IT WORKS
Targeted sampling.
Careful documentation.
Sample locations and the investigation scope are selected around the roof conditions and the questions you need answered.
01. Review the property
Discuss leak history, prior roof work, available records and access. Review the roof surface and project objectives
02. Agree on the scope
Confirm proposed locations, sampling quantity, documentation and repairs before making openings.
03. Sample & document
Open selected locations, examine the exposed assembly and record accessible layers, thicknesses and conditions.
04. Repair & explain
Repair the sampling openings with materials appropriate for the roof system and discuss the documented findings.
A ROOF CAN CONTAIN MORE THAN ONE SYSTEM
Understand the assembly.
The diagram illustrates a simple roof assembly. Existing roofs may contain multiple membranes, older roofing layers and different insulation materials—as the project photos demonstrate.
USEFUL ANSWERS FOR YOUR PROJECT
Before you commit to the next roof.
01. Investigating recurring leaks or suspected concealed moisture.
02. Evaluating an existing roof before repair, replacement or a proposed recover.
03. Clarifying undocumented roof layers and insulation thickness.
04. Supporting project scope development with location-specific observations.
What a sample can—and cannot—tell you
A core sample represents the location tested. It does not establish the condition of the entire roof or locate every leak.
Broader moisture assessment, additional samples, laboratory testing or engineering review may be recommended when the findings require it. These services are discussed separately.
Insulation thickness alone does not establish the assembly’s R-value or code compliance. Existing warranties and manufacturer requirements should be reviewed before invasive testing.
COMMON QUESTIONS
Before we open the roof.
01. Will the core sampling openings be repaired?
Repair of the sampling openings should be included in the agreed scope. The repair method depends on the existing roof materials and condition. Any warranty requirements should be reviewed before sampling.
02. How many samples will my roof need?
The quantity depends on roof size, changes in the assembly, observed conditions and the purpose of the investigation. DMG will discuss a proposed scope rather than assume one sample represents the entire roof
03. Does core sampling find the source of a leak?
It can reveal conditions within the sampled assembly, but it may not identify the point where water enters. Leak investigation may also require inspection of seams, flashings, penetrations and other building components.
04. Can I request an investigation without hiring DMG for roof replacement?
Yes. You may request an investigation independently of a repair or replacement project. Any subsequent construction work would be discussed separately
05. How much does core sampling cost?
Pricing depends on access, roof system, number of sampling locations, repair requirements and the agreed documentation. Contact DMG with your property details to discuss the appropriate scope and a proposal.
START WITH YOUR ROOF
Request a flat roof core sampling assessment
Tell us what you need to understand about your roof. We’ll discuss the property conditions and an appropriate investigation scope.
708-866-1541
Monday-Friday 9 AM-5PM
Saturday 9 AM-5PM
Helpful details to include
1. Your name, phone number and property address.
2. Building type and approximate roof size.
3. Roof materials, age and prior repairs, if known.
3. Leak history and what you want the investigation to answer.
4. Roof access, existing warranty information and preferred timing.
Your message has been sent. For immediate service call 708.886.1541. Thank you.
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