Any problems mixing Salt with Roundup for weed killing?

Trying to permanently kill weeds and anything else growing in certain areas of my alley and sidewalks. Would it cause any toxic hazards if I mix salt and roundup to apply all at once? thanks in advance

 

Not a toxic hazard, but Roundup is for short term killing. You can use roundup (without salt) and plant few days later.

For longer term crack etc killing, you would be better to use vegetation killer designed for that.

 

Regular Roundup takes two weeks for a full kill, root and all. No reason to add salt, however using salt alone will kill everything but a longer while for the salt to leach out of the soil. Roundup does not kill seeds. Roundup comes in all kinds of Glyphosate concentrate. The higher the concentrate percentage, the higher cost. Glyphosate is now available in generic formulas. Most herbicides of other brands will be glyphosate and at any level of concentrate.

Roundup Quick Pro: It's the Diquat that make it a 24 hour kill
ACTIVE INGREDIENTS:
*Glyphosate, N-(phosphonomethyl)glycine, in the form of its ammonium salt.......... 73.3% .
Diquat dibromide [6,7-dihydrodipyrido (1,2-a:2’,1’-c) pyrazinediium dibromide] ...... 2.9%
OTHER INGREDIENTS: ............................................................................................... 23.8%

 

Roundup can cause more damage. You will require additional efforts to grow grass. I think you should go for conventional methods of weeds and shrubs removal. You can either pull out weed or use weed-killers. If the lawn is packed with weeds, you can seek for a professional help.