{"product_id":"hessian-culvert-bags-cement-and-aggregate-mix-25kg","title":"Hessian Culvert Bags - Cement and Aggregate Mix 25kg","description":"\u003cp class=\"code-line\" dir=\"auto\"\u003ePre-mixed cement and aggregate, dried and sealed in a 25kg hessian bag. Place, wet, and walk away. The concrete sets to form a solid, permanent structure and the hessian breaks down naturally, leaving no residue.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003eSupplied by Bag Boys. Bulk pricing available for trade, farm and civil contractors.\u003cbr\u003e\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eWhat they are\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003eCulvert bags are a pre-mixed cement and aggregate product, dried and bagged at 25kg. They are designed to be laid like bricks around culvert inlets and outlets, alongside drainage infrastructure, or wherever you need a fast, formed concrete structure without mixing or formwork.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003eOnce placed and wetted (either by rain or by hand) the mix sets to solid concrete. The bag itself degrades over time, leaving a clean, durable structure.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eHow to use them\u003c\/strong\u003e\u003c\/p\u003e\n\u003col class=\"code-line\" dir=\"auto\"\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eStack bags around the culvert inlet, outlet, or area requiring protection, layered like brickwork\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eSecure with waratahs, basalt rock, or rebar as needed\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eWet thoroughly, or leave for rainfall to do the work\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eAllow to set - initial set within hours, full cure over 28 days\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003eNo mixing. No formwork. No concrete truck.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eWhy hessian\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003eWe use hessian for a deliberate reason. These bags go near water - culvert crossings, farm drains, waterways, stormwater infrastructure. Other options like woven polypropylene (or plastic LDPE) do not biodegrade and they photo-degrade, fragmenting into microplastics. For a bag placed at a waterway or drainage structure, that means microplastics going directly into the water the bag is supposed to be protecting.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003eHessian is a natural jute fibre. It breaks down completely with no residue, no microplastics, and no environmental liability. For any application near water, it is the right material.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003eWe do not offer woven polypropylene or plastic LDPE in this product for this reason.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eCommon applications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul class=\"code-line\" dir=\"auto\"\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eCulvert inlet and outlet protection\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eFarm track and gateway crossings\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eRoad drainage stabilisation\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eWaterway and stream bank protection\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eScour control beneath bridges and culverts\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eRetaining structures for earthwork slippage\u003c\/li\u003e\n\u003cli class=\"code-line\" dir=\"auto\"\u003eErosion control on steeper grades where structure is needed\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eSupplied from Waikato.\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAvailable in full pallet quantities. Contact us for bulk pricing and lead times.\u003c\/p\u003e\n\u003ch2 class=\"code-line\" dir=\"auto\" id=\"specifications\"\u003eSpecifications\u003c\/h2\u003e\n\u003ctable class=\"code-line\" dir=\"auto\"\u003e\n\u003cthead class=\"code-line\" dir=\"auto\"\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003cth\u003eDetail\u003c\/th\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody class=\"code-line\" dir=\"auto\"\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e25kg per bag\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eFilled dimensions\u003c\/td\u003e\n\u003ctd\u003e400 x 300 x 100mm (approx)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eBag material\u003c\/td\u003e\n\u003ctd\u003eNatural hessian (jute)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eFill\u003c\/td\u003e\n\u003ctd\u003ePre-dried cement and aggregate mix\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eCoverage\u003c\/td\u003e\n\u003ctd\u003eApproximately 17-19 bags per m2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eCure time\u003c\/td\u003e\n\u003ctd\u003eInitial set within hours; full strength at 28 days\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eBags per pallet\u003c\/td\u003e\n\u003ctd\u003e40\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eSupply\u003c\/td\u003e\n\u003ctd\u003eFull pallets; bulk pricing available\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr class=\"code-line\" dir=\"auto\"\u003e\n\u003ctd\u003eOrigin\u003c\/td\u003e\n\u003ctd\u003eFilled at Hamilton, Waikato\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch2 class=\"code-line\" dir=\"auto\" id=\"faq-section\"\u003eFAQ Section\u003c\/h2\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eWhat's the difference between your culvert bags and concrete culvert bags from merchants?\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eSame product, different bag. Other suppliers culvert bags use a paper bag with a similar cement and aggregate mix. Paper and hessian both biodegrade cleanly and either works well near waterways. We use hessian because it handles moisture better during installation and is more forgiving in wet or damp site conditions.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eWhat about woven polypropylene culvert bags?\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eWe do not offer them. Woven polypropylene does not biodegrade - in New Zealand's UV conditions it fragments into microplastics. For bags placed at waterways and drainage structures, we do not think that is an acceptable trade-off. Hessian does the same job and leaves nothing behind.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eAre these the same as compost or seed-filled erosion control bags?\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eNo. Compost socks, silt socks, and coir logs are filled with organic material and are designed for embankment revegetation. The fill retains moisture and seed germinates through the mesh over time. Our culvert bags are a cement and aggregate product that sets to permanent concrete. Different application, different result.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eCan I use these on a steep bank or slip-prone area?\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eYes. Culvert bags work well for earthwork retaining where a heavier structure is needed. For very steep or high-load areas, consult your engineer, but as a first-line retaining measure they are well suited to slips, eroding banks, and drainage channels.\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eDo you supply to farms and rural contractors?\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eYes. Most of our culvert bag orders are B2B - farm supplies, rural contractors, and civil contractors. We can quote per pallet or per project. Contact us at\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"mailto:tradesales@bagboys.co.nz\"\u003etradesales@bagboys.co.nz\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003e\u003c\/p\u003e\n\u003cp class=\"code-line\" dir=\"auto\"\u003e\u003cstrong\u003eHow many bags do I need?\u003c\/strong\u003e\u003cspan\u003e \u003c\/span\u003eAs a guide, approximately 17-19 bags covers one square metre. For culvert inlet and outlet work, most standard residential or farm culverts require between 20 and 60 bags depending on pipe size and depth of scour protection needed.\u003c\/p\u003e","brand":"Bag Boys Limited","offers":[{"title":"Default Title","offer_id":54036968472771,"sku":null,"price":17.99,"currency_code":"NZD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0249\/4945\/6973\/products\/SandbagHessianNZ.jpg?v=1680403208","url":"https:\/\/bagboys.co.nz\/products\/hessian-culvert-bags-cement-and-aggregate-mix-25kg","provider":"Bag Boys","version":"1.0","type":"link"}