What is Hair Porosity?
Simply put Hair Porosity is the hair’s ability to absorb and retain moisture.
If hair is ‘High Porosity’, it means that due to its raised cuticle layer it can absorb too much moisture and also leaks out moisture so its retention is hampered. In most cases this is normally damaged hair. One of the characteristics of high porosity hair, is it lacks shine, lustre.
‘Low Porosity’ on the other hand is hair that is resistant to absorbing moisture, and products just seem to ‘sit’ on the hair, this is because the cuticles in this case are extremely compact and overlapping, but once the moisture is in it does not leak out like it does with high porosity hair, so this hair type has good retention abilities. Low porosity hair often looks very healthy, but in a lot of cases it lacks elasticity.
Hair that has ‘Normal or Average Porosity’ is obviously the ultimate hair porosity to have, here the hair cuticles are compact but not to an extreme like in the case of low porosity hair, normal porosity hair absorbs and retains moisture adequately. The hair looks healthy and resilient and full of bounce, and has elasticity.
Why is it important?
Porosity is a critically important factor in determining one’s hair care. Moisture determines the health of our hair. This is more evident in wavy, curly, kinky or highly textured hair. This is because moisture defines and shapes the curls, the inability to absorb or keep moisture in the hair shaft will undermine even the most valiant efforts to maximise curl potential.
If you don’t know your hair’s porosity, you won’t be able to make the best product and maintenance routine choices to maximize the amount of moisture your hair retains, since lack of moisture is one of the biggest causes of frizzy, dry, dull hair.
The texture of your hair is not an indication of its porosity. Different degrees of porosity can be found in all hair textures. For example, although coarse hair normally has a low porosity and is resistant to chemical services, coarse hair can also have high porosity too, either naturally or as the result of damage or previous chemical services.
How does this affect treatments?
Hair with low porosity is considered “resistant” hair. Low porosity hair is much more difficult to process, it is resistant to chemical services, and has a tendency to repel products rather than absorb them. Chemical services performed on hair with low porosity require a more alkaline solution than those on hair with high porosity, this is needed in low porosity hair to raise the cuticle and permit uniform saturation and penetration.
Normal porosity hair, allows for normal processing when a chemical service is performed – according to the texture – and will readily absorb and retain product properly formulated for this hair type.
Hair with high porosity is considered “overly porous” can occur naturally, but is usually the result of previous over processing. Other factors that can also affect porosity include heat damage, chlorine/hard water/mineral saturation, sun damage, or use of harsh ingredients. Overly porous hair is dry, and fragile. High porosity hair processes very quickly and can be easily damaged even further if extreme care is not taken when a chemical service is performed. Although overly porous hair absorbs product quickly, it is often dry as the open cuticle does not allow for product retention within the hair shaft. Chemical services performed on overly porous hair require more acidic solutions with a lower pH level, which will help to prevent further over processing.
Porous hair accepts hair colour faster and permits darker colour than less porous hair; however, although overly porous hair takes colour quickly, colour also fades quickly. While hair with low porosity is difficult for chemicals to penetrate and takes a longer processing time, the colour will last much longer.
How to assess hair Porosity:
In order to test accurately for porosity, use three different areas: front hairline, side hairline – in front of ears, and near the crown
You can check porosity on dry hair by taking a strand of several hairs from four different areas of the head (front hairline, in front of the ears, crown and nape). Slide the thumb and index finger of your other hand down each hair strand from end to scalp. If it is smooth, you have normal porosity. If your fingers move very fast up the hair strand and it feels exceptionally slick, dense and hard, you have low porosity. If your fingers “catch” going up the strand, feel like they are ruffling up the hair strand, or if the hair strand breaks, your hair is overly porous.
For this assessment, you want to feel your hair while it is wet, and the technique is the same for all hair types.
After washing your hair, squeeze or blot excess moisture from your hair so that it is not dripping, but leave it as wet as possible.
If it feels rough or has a “straw-like” texture, your hair is not very porous.
If your hair simply feels wet, you have normal hair porosity.
If your hair has high porosity, it will feel sticky, almost as if you had not washed all products out of your hair.
Wash and condition hair. Dry hair with a towel or t-shirt. Do not add any products to your hair.
Separate hair strands and gather one strand. Capture the hair strand with your index finger and thumb.
Run your index finger and thumb up the hair shaft. Start at the end of the hair and run down to the root.
Determine hair porosity. Overly porous hair catches down the hair shaft. Normal porous hair is smooth down the shaft, and low porous hair feels slick.
After washing, conditioning and detangling your hair, take a single strand of hair from your detangling comb; make sure it is clean and free of any product. Place it into a bowl of water. Observe the hair for up to one minute to see if it floats. Hair should not sink. If it does, the hair is porous.
Hold a section of your clean hair, ideally that you have washed the night before. Do not Blow Dry it, as this can cause damage to the hair.
Spray the section with a mist of water. Look to see if the hair absorbs the mist. The water should roll off the hair immediately, indicating a non-porous or resistant condition. If it absorbs and disappears, the hair is porous.
What can I do about my damaged porous hair?
Unfortunately, porosity issues stemming from irreparable hair damage cannot be permanently corrected, only time can truly mend damaged hair.
You can, however, create a temporary fix until the damaged part grows out by “reconstructing” the hair shaft with protein treatments. Protein fills in any holes within the cortex (inner layer of the hair) and also helps to fill in the gaps exposed by a raised cuticle.
Individuals with coarse hair, however, must be cautious: putting additional protein on coarse hair can dry it out even more. For those with a coarse texture, acidic treatments such as apple cider vinegar rinses help to close the cuticle and are likely a better alternative.
So really, what does this mean to me?
It means you need to determine your hair texture and your hair porosity, and then think about what types of products are best suited to your particular hair type. Other factors will come into play, but these two hair properties are the most important properties to know.