An insect screen on a sliding window sounds simple: a panel of mesh that keeps mosquitoes out while the breeze comes in. Most product pages stop there, because the simple story sells. The useful story is different. A sliding window screen is not an accessory you bolt on later. It is a second moving panel that shares the same track and the same wall width as the glass, and that one fact changes how you should size the window, how you should specify the mesh, and when you should stop paying for features you will never use.
ALPES builds the screen into the window system rather than leaving it for an aftermarket clip, and that is the right place for it. This article explains what a china mesh sliding window supplier should hand you as part of the order, what the mesh grade numbers actually mean, and where the honest trade-offs sit.
A horizontal sliding window works by letting one panel travel sideways past a fixed one. When you add a screen, you are adding another panel that also has to travel sideways. It does one of two things, and both matter:
This is why a screen should be specified with the window, not discovered after the window is installed. Once the opening is cut and the frame is set, the screen is whatever will fit, not whatever you would have chosen.
The ALPES TS130 side-press sliding window lists screen options as part of the product, not as an accessory page you find elsewhere: Black/Grey 80# stainless steel mesh and Black 40# stainless steel mesh, with extended functions that include an inward-opening sash mesh, an inward/outward opening mesh, an integrated glass railing, and an anti-theft grille. Building the screen into the same system matters for three reasons that aftermarket screens struggle with:
The TS130 also carries a four-sided continuous sealing strip with a side-pressure rubber seal rated at casement level, a 6060-T66 profile, and a PA66GF25 thermal break. None of that is the screen's job, but it is the context the screen sits inside: the window is already a sealed, thermally broken unit, and the screen is an added layer on top of it.
The hash mark on the mesh grade is a thread-count descriptor used across the trade: roughly the number of wires per inch in one direction. A higher number means a finer weave. ALPES offers both a 40# and an 80# stainless steel mesh, and the choice is a straight trade-off, not a better-versus-worse:
| Mesh grade | What it keeps out | What you give up | Use it where |
|---|---|---|---|
| 40# stainless steel | Flies, mosquitoes, common household insects | Larger open area, so the finest no-see-ums can pass | Most residential sites, best airflow and visibility |
| 80# stainless steel | Finer insects, including many small biting midges | Less airflow and slightly less light through the weave | Coastal, lakeside, or humid sites with tiny pests |
As a directional reference rather than an ALPES figure, the common fibreglass standard sits around an 18 by 16 weave and is sized to stop flies and mosquitoes but not the smallest midges. The point is not the exact count, it is the direction: every step finer blocks smaller insects and costs you air and light. Pick the coarsest mesh that still stops the pest you actually have.
ALPES uses stainless steel mesh on its sliding window screen options. Stainless (commonly grade 304 in the trade) is the right call for coastal and high-humidity sites because it does not rust the way plain steel does, and it holds its shape. The trade-offs to know:
| Material | Strength | Weakness | Best fit |
|---|---|---|---|
| Stainless steel (304) | Durable, corrosion resistant, holds tension | Heavier, less flexible, dearer than fibreglass | Coastal, humid, long-service sites |
| Fibreglass | Light, flexible, clear, economical | Can sag, less resistant to pets and impact | Interior, low-risk, budget-first openings |
| Aluminium | Rigid, holds shape, used in ember-risk zones | Can dent, heavier, less flexible | Where the local code names aluminium mesh |
It is tempting to think the mesh adds a layer of sealing. It does not change the window's air and water performance, because the screen sits in its own track, not in the gasket line that the four-sided continuous seal controls. What the screen actually changes is:
None of that is a reason to skip the screen where you need it. It is a reason to place the screen on the same drawing as the window, so the opening, the track, and the cleaning access are all decided once.
Not every opening needs the finest mesh and the most elaborate mechanism. In a low-pest climate, a 40# stainless mesh on a simple sliding or inward-opening sash is plenty, and paying for 80# everywhere or a pleated retractable unit on every window is money spent on a problem you do not have. Retractable and pleated systems add a cassette, a spring, and a guide that can fail and that you then have to service. They earn their keep on wide openings where a rigid panel is awkward, not on a standard bedroom slider.
The honest rule: match the mesh to the pest, match the mechanism to the opening width, and stop there. A screen is a bug barrier and a ventilation aid. It is not insulation, not a lock, and not armour.
Because the screen shares the track and the reveal, it belongs in the window order. A useful data block to send with the RFQ:
| Field | Fill in | Why it matters |
|---|---|---|
| Window model | TS130 side-press sliding window | Confirms screen is an integrated option, not aftermarket |
| Opening mode | 1 fixed + 1 movable / middle fixed + 2 movable | Decides how much glass can be open with the screen in play |
| Mesh grade | 40# or 80# stainless steel | Sets insect size stopped versus airflow lost |
| Frame colour match | Same as window (e.g. ice-cream white) | Avoids a visible mismatch bar on the elevation |
| Screen type | Inward-opening sash mesh / sliding / fixed | Decides whether glass-open and screened can happen together |
| Cleaning access | Removable / inward-opening | Decides long-term maintenance cost |
| Topic | Status | Why |
|---|---|---|
| Profile and thermal break | Published: 6060-T66, PA66GF25 | Real, verifiable window-system values |
| Mesh grades offered | Published: 40# and 80# stainless steel | Real catalogue choices |
| Screen warranty term | Ask for it in writing | Not published; a number here would be a guess |
| Mesh tensile or insect-size rating | Ask for it in writing | Grade number describes weave, not a certified stop size |
| Security performance | Not claimed | A fly screen is not a security screen; ask for a rated product |
Does the screen reduce the window's insulation?
No. The screen sits in its own track and does not sit in the gasket line, so it does not change the window's air or water seal. It changes openable area, light, and cleaning access, not the thermal break.
Can I open the glass and still be screened?
On a standard single-track slider, not at the same time. The inward-opening sash mesh is the option that lets the sash open inward with the mesh attached, so the opening stays usable and screened together.
Is 80# mesh worth it everywhere?
Only where the smallest pests demand it. Finer mesh blocks smaller insects but reduces airflow and light. On a typical residential site, 40# is usually enough.
Will stainless steel mesh rust near the sea?
Grade 304 stainless resists corrosion far better than plain steel and is the sensible choice for coastal and humid sites, but no metal is immortal in a salt environment. Confirm the exact grade and finish with the supplier for your exposure.
Is a stainless screen a security screen?
No. A heavier mesh resists dents and pets, but forced-entry resistance needs a different product with its own fixings and test standard. Ask for a security-rated screen by name if that is the requirement.
Should the screen be ordered with the window?
Yes. Because it shares the track and the reveal, specifying it with the window means the opening, the colour match, and the cleaning access are all decided once, and gaps that let insects in are designed out rather than trimmed on site.
