AIBU to paint south facing windows with chalk paint as a temporary shading hack?

[JennyForeigner]

Just curious. I was reading an article on solar shading and was surprised it doesn't mention good old fashioned limewash, or the modern equivalent - chalk paint.

I've got a garage full of Annie Sloan, which I already use on a bathroom window to obscure it. A very quick bit of research says painting the exterior of my south facing French windows with chalk paint would cut absorbed heat by up to 90% compared to 40-60% for closing the curtains, and would wash off at the weekend.

Obviously I would recommend it as a solution for people in upper story flats or anything, but have I hit on a genuinely affordable and useful idea? How to shade your home

I'm using pillow cases as external shades on my kitchen's little casement window that has no blind/curtains and gets full sun, just tucked into the top and then the closed window holds them in place.

I’ve put a fitted single sheet over our kitchen skylight! Happens to fit perfectly, bizarrely.

I’ve cover all our windows with oddments of material - kids complained it was the blitz or ready for zombie apocalypse- then they opened the door, and realised they had just let a waft of hot air in!!

Instead of paint you could try using Cif/Jif.

It’s this stuff. Foil insulation roll.
https://amzn.eu/d/0dJF8V9B

That’s really weird then. It definitely looks like a specifically directed ray.

Do you have mirror chrome door handles?

Thank you!

How did you fix this to the windows? We have massive bifold doors but the house it still warm despite the internal blinds.

Another quick idea - if you've got a patio umbrella up at the mo, drag it really close to the windows/french doors or what ever you have and tilt it (away from house) so that it shades the glass.

When it's too hot to sit outside under it it earns it's keep keeping the sun off the patio doors.

I just used masking tape.

I remove the coverings at night so the tape doesn’t leave a residue. If it does, put a bit of vegetable oil on a cloth and rub off. Wash with warm soapy water ready for the next day.

I think some people use suction cups too. Maybe even magnets but you’d have to stick those onto the glass.

Yes I do this too as well as my DIY foil blinds.

Think more houses will be installing external shutters in future!

Just hang a sheet on the outside of your windows.

No, black wrought iron. I wish I knew what caused it - it would be comforting to th8nk that it might not just be sunshine because we have young children, a very flammable thatched cottage and finding it really creeped me out.

I had this stuff delivered yesterday from Amazon (not sure if exact same supplier/brand)! It truly works, it has made SUCH a difference today (if a bit gloomy inside)

My roll came with 3M sticky pads, took me 5 mins from opening it to having up on the window - just cut the roll to size and stick it on. if you have a look at the pictures it should show if it comes with sticky patches or not.

I've used water to stick foil insulation 'blankets' to my west-facing windows. They're on the inside, but the house is absolutely cooler than it would be normally.

Does anyone know whether covering windows on the outside makes a big difference compared to covering them on the inside?

We’ve got our skylights covered in old sheets on the outside but our south-facing bedrooms upstairs are just vile sweaty pits. We have white sheets up on the inside but just wondering if moving them outside would help??

@Squirrelsnut@SpidersAreShitheadsjust been reading sticking foil on the inside can crack the windows so it should go on the outside to keep the glass cooler

I had that on the inside of my blackout curtains where they’d baked in the sun. They also were on a pole which wasn’t flush with the windows and created a heat vacuum in the space between.

I certainly think the absolute best way is to block sunlight from hitting the windows on the outside for proper heat reduction.

Interestingly, in my west facing be-windowed flat, the one that gets it least although it’s still too hot, is the bathroom because the glass is opaque.

I do this every summer. I’ve also taken to putting an emergency foil blanket on my westfacing glass back door which gets the full glare until sunset. It may look like a crack den but it works.

You need to be really careful about reflecting the heat from the foil into the glass, especially with double glazed windows. It can cause cracks.

Foil on the outside only!

Yup - outside ALL the way. You need to stop the sun heating the glass. It helps hugely.

that’s why external shutters in hot countries such as Spain and Italy are common.

We have a large sail across the back of our bungalow where our French doors, kitchen and dining windows are, dramatically reduces the heat inside.

I think I love OP for using limewash and avoiding amazon.

(For once, living in a north-facing stone building with no double glazing feels like a wise decision.)

I wonder about a beautiful large folding screen?

Way more toxic than limewash

I’m in Australia where many houses have external blinds for hot sunny days to stop the sun reaching the glass windows.
Having the inside curtains closed helps to a degree, but you get heat build up inside between the glass and the curtain which will eventually heat up the room.
Definitely shade outside the windows will help keep your homes cooler - good luck over the next few days!
And, as soon as the air cools down, open up the house and get air flow through.