<font color=e87400> Degraff
Many of the trailers used in this business, any business for that matter, are custom made by local manufactures. Thus all the trailers are a bit different thus we probably can't give you any solid advice on this. One trailer might be 2" frame another 4", one may have 2000# axles one may have 3000# other attributes like springs, tires tongue play in the weight allowance too. You simply need to flip through your yellow pages on this & do some of your own legwork by calling all your local trailer companies & talking to them, tell em your looking for a trailer this big x that big to carry X amount of lbs. Trailers aren't like Ford Chevy etc...
How many lbs? That's up to you too. You shared a small list above of the equipment you'll have, appears to be around 3200lbs already. (Add the trailer to that & your 4000lbs, I believe that's the limit for no brakes) Now consider the things not mentioned here. If you get serious about this you'll want to purchase a second machine. Why you might ask, well nothing sucks or cost you more than having a machine poop out on you in the middle of a job, especially if you have chems up. You'll learn that the first time you have to scramble for a water hose to rinse a 2-story wall down, or a roof off, or a couple thousand sqft of flatwork.
As far as the square footage of your trailer. Well, figure that a good pressure washer will try their best to have 2 of everything on their rig(s). So, you'll want room for that. Also you didn't mention a flat surface cleaner above, that'll take up some room, in addition you'll need room to move around & get to things & room to repair things too. Hence, the 8 x 16 x 7 is looking better. Me, I also have a generator, lights, tools, air-tools, saw, a compressor & a few other things that add to the footage & the weight.
Myself I don't like enclosed rigs or trailers. I prefer truck mounting everything. It just looks more professional & serious. Plus I don't like enclosed rigs because of equipment access. I customize boxes and covers around my primary equipment for security & protection from the elements. I always chuckle when I see the guys pulling trailers with their family Eddie Bauer. I know it's no big deal really, but when the customer sees a truck functioning primarily as a tool I think it gets their gears grinding.
You mentioned above what truck should you get. We really can't answer that definitively either. The truck depends on you. Sure you can haul what you want to with a F150 but it probably won't last too long. Your going to waste the suspension, kill u-joints & burn up the motor if you’re overloading it. Grant it this probably won't happen over night, but you will likely reduce the life of the truck by half, perhaps more if you severely overload it. One suggestion here is that if you do go with a F150 you will DEFINATELY want brakes on your trailer. I'd also say to get a truck devoted to just your business, this way your family vehicle won't wreak of bleach or dumpster pads, tis nasty stuff. You mention you need to know what the GVWR is of the truck you are considering, that information is on the vehicle spec sticker in the drivers side door jamb.
Another issue is if you exceed your GVWR & get into an accident you could find yourself at the lonely end of a lawsuit. Something to think about. Trucks cost alot depending on what you get. I picked up a brand-new 2001 F350 w/15miles, 7.2 Diesel, Auto, A/C reg cab, 220†wb w/no bed, in mid 2002 for $21K. I custom built a bed for it myself for around $1k.
Like I said in my original post to this. You might want to consider getting in cheap at first & then expanding afterwards. You can find a used 1-ton truck for a song & toss your equipment in the back. You can find used equipment like it’s going out of style. Heck every week it seems at least one person is posting up on a forum or ebay a rig for sale, many are almost brand new, guys that just dove right in. Not trying to belittle you but statistically speaking, the odds are greatly against you succeeding past a couple of years. Look at this forum, there are 2800 registered users yet you will only see maybe 20 that post regularly that are registered over 2 years. That sort of says it for it’s self. If you start cheap & your bubble bust at least you won’t have too much gum on your face.
In the end, there are many many variables to consider when putting a rig together. I’ve built many a rig in my time, I’ve been at this over 10 years. Still though, for me putting together a new rig is a daunting task. I’d guess it probably is for any veteran contractor. Perhaps asking us isn’t the best idea. We all have experience with this equipment & all like this like that & that like this, perhaps we’ve grown used to one thing & hate another, most will probably agree though that their next rig will be a little different (mine always have, never a match) some may look the same to the passerby but be quite different in reality. I’ve seen big rigs on little rinky-dink trailers & little rigs on big trailers. I have a rig that even makes me laugh sometimes when I look at it. It’s a ugly little 84' nissan flatbed rig but it’s fully loaded with 18hp 4000psi, 5gpm, Surface Cleaner, little tuff heater, 3000w 6hp generator, 300’ 2wire hose on elec hanes reel, 300’ water hose on manual summit reel, 200’ speedair chem hose on a RO swivel reel, 2 shurflow pumps, 2 sets of halogens, 200' ext cord, misc tools, 5g buckets for chems, gas cans & a few other things too, no tank though & a fairly beefed up suspension. The rig is ugly as hell, but who cares, when it was in use it was only out at night anyway. Other guys used to do drive-by’s & laugh at it, I could see it on their faces when I used to take it out & had my guys come in laughing about it too. The joke was on those other companies though cause that little sucker would get the job done & make just as much $scratch$ as my $40k rig & I only have about $5k in that whole rig truck & all, plus it got 27mpg. To make it funnier many of my chuckling competitors were missing elements I had, like no surface cleaner, or no heat, no generators, no lights, or only 11-13 hp motors, heh, used to crack me up. Point there is, you can do alot with alittle if you need to.
Anyway. Do what you have to do to get going, you can always expand &/or rebuild later, but if your going to make a substancial investment out of the gate, then do it right & don't sell short on the truck or trailer arena's. Take your time & do plenty of research. Sounds like you have no experience in this field so perhaps you should learn to walk before you try & run.
GL
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