This Hack To Darken A Room Without Blinds Or Curtains Could Crack Your Window

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We all have moments when the sun beaming through the window is a bit uncomfortable. If you're looking for ways to keep your bedroom dark without buying blackout curtains or blinds, you might have stumbled across this viral hack. All across social media, DIYers have been showing how they block out light (and keep their spaces cooler in the summer) by securing sheets of aluminum foil to their windows. The problem is, this could cause your window to spontaneously crack — so not only is this hack a serious safety risk, it could also wind up being an expensive fix.

Aluminum foil is fantastic at trapping heat. If you press a sheet of aluminum right up against your window, it will reflect most of the sunlight coming in right back onto the glass. The trapped warmth makes the window glass heat unevenly, creating thermal stress, which eventually causes your window to suddenly crack from the heat without warning. This can add to the list of home safety hazards to be aware of (and it'll likely come with a hefty repair bill).

If you're set on using aluminum foil, you should put it on the outside of your windows instead of the inside. This will allow the foil to reflect the sun before it reaches the window, effectively protecting your windows from the heat, rather than making the glass hotter. However, putting foil on the outside of your window isn't as easy as using it inside. If you want to block out sun from the inside of your home, you should try aluminum foil alternatives that won't cause thermal shock.

We can't blame anyone for wanting ways to keep their windows darkened without blackout curtains. After all, curtains require installation, are difficult to measure, and can be expensive. Plus, if you already have existing curtains, you may want a blackout solution that doesn't require you to swap them out. Thankfully, there are a few options to try in place of aluminum foil.

When blocking light from the inside of your windows, opt for a material that doesn't reflect heat as much. Cardboard is a great choice — cut a few pieces to fit your windows, and slide them right inside the window frame. You can use painter's tape to secure them. Foam insulation is also a safe option for keeping your space dark and cool. You could even hang a blanket over your windows in place of curtains. All of these options are easy to put up and remove, and are much safer than aluminum foil.

If you do decide to look for blackout curtains to help you get the best night's sleep instead, sites like Amazon, Target, and IKEA offer a variety of options that start at around $15 for a pair — like the NICETOWN Grommet Blackout Curtains on Amazon. Curtains are the best long-term solution for blocking out light. Most importantly, they won't shatter your windows.