A common practice of many do it yourselfers is to buy extra building supplies and store them for later use. While this works well for nails, screws, plywood, and electrical wire, it doesn’t hold true for perishable materials like paint, caulk, and drywall compound. Even under ideal conditions, paint may last for 7 to 10 years, drywall compound will last for a few years, and caulking and sealants a year or two at best.
Paint Storage and Shelf Life
Most homeowners will hold on to paint forever to touch up small areas but over time the pigments can separate and change the color of the paint. Latex paint can last up to ten years if properly stored, but five to seven years is probably the maximum life expectancy. Oil paint can last as long, but after the paint has been opened, the air inside can cause a hard film to form. This film will actually protect the paint underneath, but it must be removed before use.
To determine if the paint is still useable, see if there is an expiration date on the can. If there isn’t a date, open the can of paint and smell it. Some paints contain a protein found in milk known as casein which can turn rancid if stored improperly of if it is too old. Mold may also be visible on the surface of latex paint.
Next check the consistency of the paint by dipping a clean paint stirrer into the paint and see if there is sediment on the bottom of the can. If the pigments have settled out you can try mixing the paint. If the sediment is too thick and cannot be loosened from the bottom of the can, the paint should be discarded.
If the paint smells fine can be mixed paint a small area on a scrap of wood or drywall and allow it to dry completely. If you notice any defects such as sediment or streaking, you should not use it. If the color and finish look good, check the label to see what the average drying time is for the paint. If the paint does not dry completely or takes too much time to dry, you should not use it.
- Label each can of paint with the date of purchase or when it was used.
- Protect oil, latex, and acrylic paints from freezing although some oil paints can take lower temperatures without any adverse effects.
- Seal the cans completely. Any air will cause the paint to dry out.
- Do not keep paint in your garage if you expect freezing temperatures.
- Flip the paint cans every year to keep sediment from collecting on the bottom of the can. You may also want to shake the can for a minute or two to remix the paint.
Caulk - Storage and Shelf Life
Most caulking and sealants will have an expiration date printed on the side of the tube. Remember to look for this date as the caulk may have been on the shelf for several months before you buy it. It is also better to buy only what you need for your project and return any unopened tubes.
When stored in the original unopened containers at or below 90°F most latex caulk has a shelf life of 12 months from date of shipment. Where high heat and humidity are a factor, special precautions must be taken. Store product in a covered, well-ventilated warehouse and avoid excessive heat conditions. Storage in high heat, high humidity conditions may reduce shelf life by up to 30%. Tubes should always be stored with the nozzle tip pointed upwards. The caulk should not be kept near the roofline of a shed or garage to prevent overheating the material during sunny, warm conditions. Latex caulk should be protected against freezing as it is water-based and freezing will cause the caulk to separate and reduce its workability and effectiveness.
Most silicone or acrylic caulks and sealants have a shelf life of 12 months when stored between 40 and 95°F. While some old timers suggest freezing silicone caulk to extend its life whether opened or unopened, freezing damages modern formulations just as with latex caulking. The tubes should also be protected from moisture is the tubes are constructed out of foil-faced paper. Any air or moisture that gets into the tube can cause the caulking to begin curing and reduce the workability of the material. Commercial and industrial heat-cured caulks are often refrigerated, but these are not common for residential use.
Opened caulk tubes can be sealed with the original cap, a stainless steel nail, copper wire, screw, or a wire nut. The important thing to remember is to remove any air that is inside the tip. If you use a standard nail or screw to seal latex caulk, it will rust and discolor the caulk. Squeeze out the caulk from the tip before using it again. Also, you may have to cut the tip again to make it larger to remove any solids that have formed inside the tube.
Caulk Saver can be purchased at hardware stores and home centers
Drywall Compound Storage and Shelf Life
The most common type of drywall compound, or spackle, for do it yourselfers is pre-mixed in 1 or 5-gallon buckets. These buckets may have an expiration date printed on the side and most manufacturers have a shelf life to 9 months to 1 year.
Drywall compound is a mixture of gypsum, water, vinyl, and other materials that will evaporate and harden when exposed to the air. To keep the compound maintain the integrity of the compound it is most important to keep air away from the material. Make sure that the lid is securely locked in place. You may also want to cut a piece of plastic to fit inside the bucket and set it on top of the spackle before you seal it. You may also smooth the surface of the compound and pour water on top to form an airtight layer. Remember to pour off the water before you use it next time.
Protect the drywall compound from freezing. If the material freezes, it will become very grainy and the liquids will separate out of the mixture once it thaws. It may still be used, but it can be difficult to work with and the strength and bond of the compound will be reduced. Freezing will void any manufacturer’s warranty.
In conclusion, even when paints or caulking have expiration dates, you should test them whenever possible and they still may be used after their expiration date but care must be taken as if the material is used and it doesn’t work, you will have a difficult time removing it, especially when it comes to silicone or latex caulk.