help withpricing digging in forestry tracks/rides

[matelot]

why are you putting geotextile down? is the ground soft/ wet?

 

I'm a civil engineer (speciality road construction), we generally only use geotextile when we are putting capping etc onto soft stuff (the stuff you can push a stick into).

 

It might be cheaper to not use geotextile and use more stone instead? or even just top up the areas that sink with more stone.

 

if the ground is only slightly soft I'd consider a geogrid instead.

[Charlieh]

EWGS standard costings for roads had been removed as all infrastructure has to go through the woodfuel wig based on three quotes now rather than standard costs. The CD mentioned will give an indication of estimated costs per mtr which is more realistic than the old standard costs.

[Stoke Wood Project]

The civil engineer above should know that geotextile is cheap per metre.compared to adding more stone!! Very cheap. When I bought 5 rolls for my woods, I think it was about £100 for a roll. I think it was 4.5 m wide, and 100m long. Very cheap, and if your track needs to be 4m wide, then it could be expected to carry heavy vehicles. 150mm of stone soon moves about, and mixes with the soil underneath. Definitely use a geotextile! Or at least double the thickness of stone. Just sayin!

I have pretty clayey soil btw.

[Stoke Wood Project]

In fact even with a geotextile, you might find 150 mm too thin. My track only has 4x4's on it, and is only 2-2.5m wide, and has soft spots which need topping up, so remember to put in plenty of drains or culverts to carry water away.

[matelot]

The civil engineer above should know that geotextile is cheap per metre.compared to adding more stone!! Very cheap. When I bought 5 rolls for my woods, I think it was about £100 for a roll. I think it was 4.5 m wide, and 100m long. Very cheap, and if your track needs to be 4m wide, then it could be expected to carry heavy vehicles. 150mm of stone soon moves about, and mixes with the soil underneath. Definitely use a geotextile! Or at least double the thickness of stone. Just sayin!

I have pretty clayey soil btw.

 

geotextile can be expensive if you don't actually need it.... I'd also assume the cost of stone for the OP is low - he is working at a quarry.

 

this is a document that shows how the FC recommend how to construct forest track (with indicative costs), not a single mention of geotextile....

 

http://www.forestry.gov.uk/pdf/ODW703.pdf/$FILE/ODW703.pdf

[matelot]

In fact even with a geotextile, you might find 150 mm too thin. My track only has 4x4's on it, and is only 2-2.5m wide, and has soft spots which need topping up, so remember to put in plenty of drains or culverts to carry water away.

 

have you considered a geogrid? you'd have to make sure your aggregate size would interlock with the grid. obviously you'd need a crushed aggregate as well.

[Tommy 7840]

some great comments thanks guys.The spec from the commision who are sorting the grant etc is to use geotextile i think the farmer probably wont buy any to be honest so really need to work out a costing to scrape of existing area then dig stone out of old quarry then level the stone on the road so need to work out a price per metre.

[LGP Eddie]

Some interesting points here, and the Geotextile one is really worth some consideration.

 

I'd firstly assume that as Stone is being dug from a borrow pit, you will either utilise some form of grading device, even it's as simple as a riddle bucket to get you some basic grades of stone?

You may be lucky and have something that produces a nice material straight out of the ground, but sometimes it will pay to separate some to get a larger/cleaner grade for any problem areas.

 

With regard to Geotextile, it must be said that is some total crap stuff now available out there! You can get both the woven and non woven versions now for not much over £100 per roll, and in some basic applications it's fine, but some is only ok for putting under mulch in a landscaping application.

It's always a balance between cost and the actual application and I'm a firm believer in Geotextile, but it's no substitute for getting the actual formation right and getting some decent size stone in where required.

Many make the mistake of putting cheap thin Geotextile down and then place large clean angular material straight on top that will punch straight through it.

I've done temporary roads across grass with a decent thickness genuine Terram and a well graded stone, and you can literally grade the stone back off, then roll the Terram back up off the grass. Try that with the £100 a roll stuff and it will be punched through all over.

 

There is no substitutes for getting anything soft dug out of a road (I'm not talking roads over a peat bog here, that can be done but different techniques entirely!) the general rule is, if it's soft at the bottom it will carry on being so all the way to the finished surface.

If it's obviously not the best ground you've simply got to get some depth into it and get some of the biggest gear possible in there. There is no substitute for getting some body into a soft spot, and some big clean stone can really transform a problem area.

 

If you are lucky and have a nice firm ground that can simply take 150mm of well graded material as in the spec, then it really should be a good enough formation not to require any Geotextile? There should be no mixing with soil, as there simply shouldn't be any present if properly prepared?

However it will certainly do no harm at this point to add the cheaper £100 a roll stuff as belt and braces.

 

If stone was readily available in quantity that could be cheaply riddled to separate grades, then I'd be looking at putting between 200 and 300mm of the larger clean material first, toped off with 100mm of the finer grade.

This would produce a much better result assuming the formation is good in the first place, and any soft spots have been fully removed and filled.

 

As for pricing per metre, it's only a guide? Until that soil starts coming off you have absolutely no idea what you're up against. Simply doing the job 'to spec' will almost certainly produce a 6" deep 4 metre wide track for the client, but will it ever be any good?

To do the job properly will require a certain amount of flexibility to deal will problem areas as they arise in the best way possible, before adding the final surface layer.

 

I've recently been doing a job on a Moorland site where using Limestone is not allowed. It was fairly obvious that it was going to be tricky, so we simply opted for some large waste material from a sandstone quarry to get some body into the road. Right or wrong the spec includes Geotextile, so we simply utilised a reasonable grade under this larger material, but my own take would be it wasn't strictly necessary? It certainly won't do any harm though.

Once down the large material transformed this piece of road, and I'll have to post a pic up of it now topped off with crushed Gritstone.

We've taken nearly 400 tonne of material over this section now without a mark on it.

 

 

Eddie.

[Tommy 7840]

thanks eddie really great tips in there im not to worried if we pit terram down or not really as long as there is plenty of stone it will be fine but im thinking there probably wont be enough to do it all as it is a long way and as you know a trailer load doesnt go far!!!! Im going to have to work out a price as the farmer needs it to put in the grant application.Some head scratching needed i think!!!!!!