The protection of concrete in winter weather from corrosive salts used to melt ice and snow has long concerned highway engineers. In searching for a solution to this problem, member companies of the National Flaxseed Processors Association, a number of State Highway Departments have shown that boiled linseed oil in mineral spirits or as an emulsion in water is an effective agent in reducing damage to concrete caused by freeze-thaw cycles and salt. These linseed antispalling compounds are usually applied to sheet cured concrete about one month after placing. Liquid membrane curing compounds containing wax and resins which are now being used in increasing amounts leave a coating on the surface that may lower the effectiveness of the linseed anti-spalling compounds. It is believed that some penetration of the boiled linseed oil from the solution or emulsion into the concrete is necessary to obtain protection. Because no detailed study had been carried out to determine whether or not linseed antispalling compounds will penetrate into concrete previously cured with polyethylene or typical commercial pigmented resin and wax compounds, work was undertaken to study the penetration of linseed oil into concrete under a variety of conditions and to correlate this information eventually with companion durability studies. Concrete blocks were prepared in polyethylene dishes according to a method developed by Sherwin-Williams Company. The blocks were immediately sprayed with a curing compound at the recommended rate and the surface of the block was covered with polyethylene. The blocks were cured indoors for seven days at room temperature. Either boiled linseed oil in mineral spirits (LASC) or boiled linseed oil emulsion (LSOE) was used. Concrete cured under polyethylene or by spraying with commercial wax or resin curing compounds and subsequently treated with either a fifty percent LASC or a fifty percent LSOE was penetrated at temperatures between 34 to 100 degrees F. Penetration of anti-spalling compounds was greatest when the concrete was treated one month after curing. With concrete up to 35 days old treated with a fifty percent solution or emulsion, all methods of curing tested gave similar penetration patterns with time. It appears that the depth of penetration of these antispalling compounds into new concrete depends more on the age of the concrete at the time of applying the linseed oil compound than it does on the curing method used.