An Honest Review of Spiderex
+ a look at alternatives
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Spiderex is a popular spider repellent spray that’s often marketed to the CCTV industry as cobwebs can obscure the camera footage and even set off movement sensor alarms.
It’s cheaper to spray the area around the camera every few months than pay someone to remove the cobwebs every week or so.
It can also be used around any property to stop spiders from setting up a home.
Spiderex isn’t the only product that deters spiders and crawling insects, but this company has carved out a niche with a catchy name and effective marketing.
I tested Spiderex in the Autumn of 2022 and this is my honest review. I’ll also closely examine competing products with similar ingredients that might be a bit cheaper.
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.
- 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:
- 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.
- 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.
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.
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.
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.
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.
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.
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.
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.
Does Spiderex Kill Spiders?
In the UK, spiders are not recognised as pests so pesticides cannot be sold to kill spiders, hence why Spiderex is marketed as a deterrent.
But yes, the ingredients in Spiderex will both deter and kill spiders and crawling insects.
Here is a quote from Spiderex:
SpiderEx has been developed to repel spiders and prevent them from nesting where it’s sprayed. The purpose is not to kill spiders but like any repellent if you spray directly onto a spider, it is likely to kill it but this is not the intention of SpiderEx.
How Long Does Spiderex Last?
Spiderex claims that their product will last up to 8 months but I feel in the rain, it will need to be applied sooner.
Indoors, I suggest applying once or twice a year, with one application just before autumn when spiders are most active.
How Does Spiderex Work?
Spiderex contains insecticides that are found in many other products (inc Permethrin), but they have also created a film/lacquer so the product persists on the surfaces it is sprayed, where it deters spiders for months.
Will Spiderex Stain uPVC Windows and Door Frames?
During my tests, it didn’t leave any permanent stains and I was able to scrub off the sheen with a sponge. I suggest testing the product first if you are concerned about staining.
Is It Safe?
Spiderex is classed as an insecticide so comes with the usual warnings:
R12 Extremely flammable.
R20/22 Harmful by inhalation and if swallowed.
R43 May cause sensitisation by skin contact.
R50/53 Very toxic to aquatic organisms, may cause long-term adverse effects
in the aquatic environment.
R65 Harmful: may cause lung damage if swallowed.
R66 Repeated exposure may cause skin dryness or cracking.
Hazard statements in full H220 Extremely flammable gas.
H222 Extremely flammable aerosol.
H229 Pressurised container: may burst if heated
H280 Contains gas under pressure; may explode if heated.
H302 Harmful if swallowed.
H304 May be fatal if swallowed and enters airways.
H312 Harmful in contact with skin.
H317 May cause an allergic skin reaction.
H331 Toxic if inhaled.
H400 Very toxic to aquatic life.
H410 Very toxic to aquatic life with long lasting effects.
EUH208 Contains PERMETHRIN. May produce an allergic reaction.
Is Spiderex Sticky?
Once dry I found Spiderex to be non-sticky. It left a film on the surface that was hard, like a fine lacquer.
Does Spiderex Harm Insects?
Yes, Spiderex is effective on most crawling and flying insects, including; ants, cockroaches, beetles, centipedes, dog ticks, fleas, flies, silverfish and wasps.
Is Spiderex Completely Invisible?
I couldn’t see Spiderex after spraying it on white glossy surfaces or my carpet, but on darker wood and brown uPVC plastic, it left a shiny, translucent film that was visible from an angle.
I could wash off the film with a sponge, and at no point did I see white marks or permanent stains, but I can’t guarantee this will be the same for you – I suggest testing it first.
Meet The Author: Daniel Woodley
Daniel has over 18 years of experience in the construction, home improvement, and landscape garden industries.
He previously worked as a project manager and has experience in managing teams of tradespeople and landscape gardeners on both small and medium sized projects.
Daniel is also a keen gardener and enjoys growing unusual plants and tending to his lawn.
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This guide was reviewed and fact-checked by Elizabeth Smith, who is a qualified horticulturist.
Explore: Elizabeth’s profile and qualifications.
How We Selected This Product
We’d heard of Spiderex from a friend who works in security as it’s become the go-to product for keeping spiders off cameras and sensors but is now being marketed to domestic customers.
The Testing Period
Spiderex was tested over a 4-month period, including autumn 2022.
Where We Tested Spiderex
We tested Spiderex on several different surfaces that we feel a typical user would spray it on.
How We Chose The Alternative Products
Both Dethlac and the CritterKill sticky traps were chosen based on our past experience with them.
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