Abstract: A portable foam compression tester for the testing of compressive yield strengths of roofing foam on-site at the point of foam application. The portable foam compression tester system comprises of a foam compression fixture attached to a standard roofing pullout tester common in the industry. The foam compression fixture consists of four support feet which, at one end, fix the foam compression fixture to the standard roofing pullout tester. A lift bar is attached to the pulling mechanism of the standard roofing pullout tester and pulls a moving platen upward as the tester is operated. A foam sample is placed on the moving platen and the sample is compressed against a fixed platen. The force required for compression of the foam sample is indicated on the force readout of the standard roofing pullout tester.