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Because these nails are not strong enough to hammer through concrete, try this option only if your concrete was secured using mortar. If your concrete object was not connected with mortar, you must use concrete screws or fasteners instead. Mortar nails are generally the cheapest attachment option for wood and concrete. Your mortar nails should go through the wood entirely and penetrate the concrete by 34 inch (1.9cm), if possible. If you can find nails that will penetrate the concrete deeper than 34 inch (1.9cm), this can create an even more secure hold. Indicate where you intend to put holes in the wood and concrete objects with a permanent marker. Using these markings as a guide, place the wood marking directly over your concrete marking. The wood should lie flat against the concrete object. Make sure the marked area you choose for the concrete object is in the mortar, not the concrete itself. Use sharp, powerful blows to work the fastener through to the bottom of the hole. Continue hammering until you drive the nail completely in and cannot hammer it further. Put on safety goggles before hammering the nail into the wood and mortar.
Use mortar nails on concrete blocks secured with mortar. Select nails that will penetrate at least 34 inch (1.9cm) into the concrete. Mark and align the holes in the wood and mortar. Drive the nails into the wood and mortar with a hammer.