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Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz
Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz

Drainage Fabric - Heavy Duty - 4' x 300' - 4.5 oz

SKU FNW4.504300
$369.44 - $369.44
$369.44
$369.44 - $369.44
$369.44
Free Shipping

Drainage Fabric Heavy Duty · 4.5 oz Non-Woven · 4′ × 300′

4.5 oz heavy-duty drainage fabric on a 4′ × 300′ roll covering 1,200 square feet. A 4-foot width in the heavy-duty 4.5 oz fabric. Non-woven geotextile providing particulate filtration for drain fields, leach fields and french drains — water through, fines held back.

Weight
4.5 ozLarger fields
Roll Size
4′ × 300′1,200 sq ft per roll
Part Number
FNW4.504300Non-woven geotextile
Filtration
ParticulateFlow in every direction
  • Particulate filtration
  • For drain & leach fields
  • Flow through the fabric body
  • Puncture resistant
  • Free shipping on all orders

Free Shipping - Please submit a Quote Request for quantities larger than listed below.

Quantity Price Per Unit
(Free Shipping)
1 $369.44
2+ $350.97
3+ $332.50
10+ $314.02

01 Non-woven geotextile · 3 oz to 16 oz

Drainage Fabric

Drainage fabric provides particulate filtration for stormwater drain fields, septic system leach fields and other drainage applications. It is a non-woven geotextile: water passes readily through the body of the fabric while the soil and fines that would otherwise clog the drainage stone are held back.

Two things decide which one you need — the weight, which follows from what is going on top of the fabric and how sharp it is, and the roll width, which follows from whether you are lining a trench or a wide field.

3–16ounce weights, all stocked

3 oz, 4 oz, 4.5 oz and 6 oz are listed individually, and 8, 10, 12 and 16 oz are stocked alongside them.

02 Why non-woven

Flow Through The Fabric, Not The Weave

In a drain field the fabric has to pass water in every direction, not just along a weave. Non-woven construction gives flow through the body of the fabric itself while filtering particulates at its face — which is why it is the specification for leach fields and drain fields rather than a woven fabric.

03 What you get

Benefits

  • Particulate filtration for drain fields and leach fields
  • High flow through the body of the fabric, in every direction
  • Keeps soil and fines out of the drainage stone
  • Non-woven geotextile construction, needle-punched
  • Puncture resistant, with heavier weights for coarser stone
  • Cushions and separates as well as filters
  • Every weight from 3 oz to 16 oz stocked
  • Roll widths from 3′ to 15′ for trenches through to wide fields
Filtration is a two-part job. Stop the soil but also stop the water and you have built a dam where you wanted a drain. Pass the water but let fines through and the stone silts up. A non-woven geotextile is specified because it does both halves at once.

04 Choosing

Which Weight Do I Need?

Every weight filters. Heavier means more strength, more puncture resistance and more cushioning, and it costs more — so the question is what the fabric has to survive, not how big the job is.

WeightWidths stockedSpecify it when
3 oz4′, 6′, 9′, 12′Standard drain field and french drain work, garden drainage, rounded or moderate aggregate
4 oz4′, 6′A step up in strength where the stone is sharper or the trench takes more traffic during construction
4.5 oz3′, 4′, 6′, 12.5′, 15′The widest choice of sizes, and the heavy-duty weight for larger fields and wide separation layers
6 oz6′Coarse angular stone, heavier loads over the fabric, and commercial drainage work
8 to 16 ozStocked — ask for sizesHeavy civil work — severe puncture risk, heavy plant, and cushioning duties
Describe the stone, not the project. How angular and how coarse the drainage aggregate is decides the weight far more than the size of the field does. Call (800) 524-4161 and tell us what is going on top of the fabric.

05 Roll sizes

Available Rolls

Narrow rolls suit trenches and pipe wraps; wide rolls suit fields and large separation layers. Matching roll width to what you are lining is what keeps offcuts and seams down.

3 oz — four widths
4′ × 300′1,200 sq ft 6′ × 300′1,800 sq ft 9′ × 300′2,700 sq ft 12′ × 300′3,600 sq ft
4 oz heavy duty — two widths
4′ × 300′1,200 sq ft 6′ × 300′1,800 sq ft
4.5 oz heavy duty — five widths
3′ × 300′900 sq ft 4′ × 300′1,200 sq ft 6′ × 300′1,800 sq ft 12.5′ × 360′4,500 sq ft 15′ × 360′5,400 sq ft
6 oz heavy duty — one width
6′ × 300′1,800 sq ft
Need a weight or size that is not listed above? Weights up to 16 oz and a wider range of roll sizes are also stocked. Tell us what you need and we will confirm the price.

06 Where it goes

Applications

Stormwater drain fields Septic system leach fields French drains Trench drains Wrapping drainage pipe Behind retaining walls Drainage stone separation Under aggregate & base stone Garden & yard drainage Cushioning over sharp ground
A leach field is the least forgiving of these. It is buried, it is not inspected, and if fines reach the stone the failure shows up as a system problem rather than a fabric problem — which is why it is worth specifying properly the first time.

07 Installation

Laying Drainage Fabric

Grade the excavation and clear anything sharp enough to puncture the fabric, then roll it out and overlap adjacent runs rather than butting them. A filter layer only works where it is continuous.

In a trench, drain field or leach field: line the excavation, place the drainage stone, then fold the fabric back over the top so the aggregate is fully wrapped. Water then enters through the fabric from every direction, and fines cannot reach the stone or the pipe perforations from above.

Behind a wall: line the excavated face and base before the stone goes in, and carry the fabric up high enough that backfill soil cannot spill over the top edge into the drainage stone.

Place fill from one side, working forward. Driving or turning on bare fabric risks puncturing it and dragging it out of position — and on a buried layer you will not know until the drain stops working.

08 You will also need

6″ Landscape Staples

Fabric that is not held in contact with the ground does not do its job. Pin the edges, every seam, and anywhere the fabric lifts — especially before aggregate goes on, when a gust or a boot can shift a whole run out of position.

6″ landscape staples are the standard pin for this fabric, and they are sold separately — worth adding to the order rather than discovering the gap on install day.

View 6″ Landscape Staples

09 Documentation

Specification Sheets

Sheets for every weight we stock, from 3 oz through 16 oz.

3 oz specification sheetPDF 4 oz specification sheetPDF 6 oz specification sheetPDF 8 oz specification sheetPDF 10 oz specification sheetPDF 12 oz specification sheetPDF 16 oz specification sheetPDF

10 Buying from us

Why Buy Drainage Fabric From Landscape Discount

Commercial grade only

Professional-grade geotextile, not a garden-centre weed mat. We never substitute another fabric or weight without the explicit consent of the customer.

Every weight stocked, 3 oz to 16 oz

3 oz through 6 oz listed individually in widths from 3′ to 15′, with the heavier weights stocked alongside them.

Widths for trenches and fields alike

From a 3′ roll for pipe wraps to a 15′ roll for wide separation layers, so the fabric matches the excavation.

We answer the phone

When you call you quickly reach a helpful, live person happy to answer your product and order questions. (M-F 5:00 am - 3:00 pm Pacific Time)

11 Common questions

Drainage Fabric FAQs

What does drainage fabric do?
It provides particulate filtration. Water passes readily through the body of the fabric while the soil and fines that would otherwise migrate into the drainage stone are held back at its face. That keeps drain fields, leach fields and french drains draining rather than silting up.
Which weight do I need?
3 oz for standard drain field and french drain work in moderate aggregate. 4 oz where stone is sharper or the trench takes construction traffic. 4.5 oz for larger fields and wide separation layers, with the widest choice of sizes. 6 oz for coarse angular stone and commercial work. 8 to 16 oz for heavy civil duties.
How much do I need?
Work out the area you are lining in square feet and match it to a roll — the stocked rolls run from 900 up to 5,400 sq ft. Allow extra for overlapping the joints, which are not optional on a filter layer.
Can I get a weight or size that is not listed?
Yes — the individual listings are not the full range. Weights up to 16 oz and a wider choice of roll sizes are stocked. Tell us what you need and we will confirm the price.
Do I overlap or butt the seams?
Always overlap. A filter layer only works where it is continuous, and a butted joint that opens under load is a direct path for fines into the drainage stone.
How do I wrap a drain field or leach field?
Line the excavation, place the drainage stone, then fold the fabric back over the top so the aggregate is fully wrapped. Water then enters through the fabric from every direction and fines cannot reach the stone or the pipe perforations from above.
Why non-woven rather than woven?
A drain field needs flow through the fabric in every direction, not just along a weave. Non-woven construction passes water through the body of the fabric while filtering particulates, which is the right property for drainage. Woven fabric has higher tensile strength but far lower flow.
Can I drive on it before covering it?
Avoid it. Place fill from one side and work forward over material already down. Driving or turning on bare fabric risks puncturing it and dragging it out of position, and on a buried layer you will not know until the drain stops working.
How do I secure it?
Pin the edges, every seam and anywhere the fabric lifts. 6″ landscape staples are the standard pin for this fabric and are sold separately.
What does shipping cost?
Nothing. Shipping is free on every order, at any quantity.