An Honest Review of Spiderex

Written by Daniel Woodley. Reviewed by Elizabeth Smith. Published to Pest Control on: 30th March 2023.

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Specifications 

Here are the key specs for Spiderex:

Pack Sizes: Single 300ml can, 3-pack, 6-pack or 10-pack.

Type: Aerosol but the liquid dries and leaves a surface film/lacquer.

Active Ingredients: 0.25% w/w Permethrin and 0.1% w/w Tetramethrin.

Suggested Uses: Hard surfaces such as; around cameras, sensors, door and window frames, skirting boards, garages, sheds and storage areas.

Warning: Flammable until dry.

The Price I paid: £11.33 per can (as part of a 3-pack).

What The Manufacturer Claims 

The manufacturer has made several claims on their website that I wanted to test:

• It’s colourless.
• Odourless.
• It doesn’t stain.
• Deters spiders and all crawling insects from the treated area.
• It lasts up to 8 months.

My Test of Spiderex

My test of Spiderex consists of two parts:

1. I sprayed a dozen different surfaces in my home to see if it left any residue and to see if it reduced the number of spiders that entered the home.
2. I asked a relative who is afraid of spiders to treat all of her door, window and skylight frames, and other entrance points with Spiderex in early autumn 2022 and to report back to me the results.

I placed sticky spider traps in the exact places where I had sprayed Spiderex to see if any spiders crawled over the product and got caught in the traps.

Here are the surfaces that we sprayed it onto:

• Brown timber window frames.
• Brown timber door frames.
• uPVC plastic window and door frames.
• Glossed skirting boards.
• In each corner of the ceiling in each room.
• Carpet (on a section in a cupboard).
• Around pipe entrance points (water, cables, services etc.)

I followed Spiderex’s instructions, kept the can 30cm from the surface, and released the product in one-second bursts.

To be extra safe, I used a piece of old newspaper to protect the carpets when I sprayed the skirting boards; I think this is good practice as I didn’t want it on my carpets.

Test Results

Applying Spiderex

When I tested Spiderex the first thing I noticed was how far it went, I purchased a 3-can pack, and I found that this was enough to treat two small homes.

The second thing I noticed was that it took a while to dry. It was touch-dry on the plastic and timber doors/window frames after about 30 minutes.

The aerosol ejected the liquid quickly, so I was able to treat all the skirting boards and window frames in a room within a couple of minutes.

What it Looks Like

I couldn’t see it at all on the white glossed surfaces or the white uPVC window and door frames where it was translucent, dry and non-sticky.

I couldn’t see it all on the carpet I sprayed it onto either.

I did find that it was more visible on the brown uPVC and timber door and window frames, where it left a slight sheen, but as part of my test, I wanted to see if the sheen was permanent, so I scrubbed it with a sponge and water – the product washed off but only after some scrubbing and it didn’t leave any persisting marks on the plastic or timber.

It did leave a slight sheen on my plasterboarded walls which were painted with matt emulsion and were very absorbent – but it was barely noticeable and only from an angle.

Waterproofness

Spiderex can be used outdoors, but I was able to scrub it off timber and plastic with a sponge, so I believe it will need to be reapplied more frequently if it’s sprayed onto a surface that’s subjected to a lot of rain. It’s not 100% waterproof, but it did not wash off with just a splash of water; I had to scrub it with reasonable effort to get it off. I would describe Spiderex as water-resistant.

Odour

Spiderex has a slightly fragranced odour, but it was more acceptable compared to similar products I’ve tested in the past.

I sniffed the product one week after it dried from a distance of 50cm, and I couldn’t smell it, so I’m confident it won’t leave any noticeable odours.

Effectiveness

I put down 14 sticky spider traps on windowsills, next to skirting boards and close to pipe and cable entry points where I’d sprayed Spiderex.

After 4 months, I checked each of the traps, and none of them contained spiders.

I can also report that I noticed far fewer spiders coming into the home during the autumn months, a time of year when I usually see quite a few.

At the 4-month mark, I also asked my friend to report back to me; here’s what she said:

This is the first autumn I can remember where I didn’t have to crawl on my floor trying to catch spiders in a glass. I’m 100% confident that this product works and I’ll be putting it down each year at the end of summer, in time for the autumn.

Summary

I’m 100% sure Spiderex is effective and I noticed a drop in the number of spider incursions, but I was very thorough in treating the entrance points; I even sprayed around cable and pipes that entered the property and the insides of all the window and door frames.

The product did leave a slight sheen on my dark brown window and door frames but I scrubbed it off and it didn’t leave any permanent stains.

It didn’t mark my cream carpets but did soak into my plasterboard walls and left a sheen mark – the next time I use it, I’ll be a little more careful around absorbent surfaces but even here it was barely visible.

I recommend Spiderex to anyone who wants to keep spiders out of their home, shed, garage or caravan but I suggest doing a test on a patch area first and being careful around absorbent surfaces such as plastered walls.

But is Spiderex worth it?

It’s currently selling at around £12 per can, which isn’t exactly cheap.

Below, I take a look at alternative products you may wish to try.

Alternatives

Dethlac

I’ve previously used Dethlac on hard surfaces around the home to stop crawling insects and spiders, and I found it very effective.

While it has different ingredients to Spiderex, it’s also a lacquer and pests stay well away from it, and if they do come into contact with it, they usually die off fairly quickly.

At just over half the price of Spiderex, Dethlac is worth considering, but there is a catch.

When I used it, I noticed it left white marks on some surfaces and the manufacturer states that it shouldn’t be used on uPVC frames. Also, on Amazon, there is a negative review from a customer who stated that it left permanent stains on his window and door frames.

I can only recommend Dethlac as an alternative to Spiderex if you only use it in inconspicuous areas, but it does work out much cheaper.

Both products leave a film on the surface which contains insecticides and bugs stay well away from it, if used carefully around entrance points, I’m confident both products will be effective.

Sticky Traps

The insect traps I previously tested are effective against all crawling insects and spiders.

The products are made from cardboard and they contain a very sticky glue on the inside which traps the pests.

None of these sticky traps will deter spiders, but I’ve placed them in my wardrobe to catch moths and under my bed when I noticed a few spiders were active in my bedroom and crawling over me at night.

As you can see from my photos below, they certainly are effective and I still have two in my wardrobe to protect my clothes.

I recommend this product to anyone who doesn’t want to spray surfaces in their home with insecticides.

Spiderex FAQs

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